DRUGS IN THE HUMAN BODY.

Thanks to medical and drug research, there are thousands of drugs that help people. Antibiotics and vaccines have revolutionized the treatment of infections. Medicines can lower blood pressure, treat diabetes, and reduce the body's rejection of new organs. Medicines can cure, slow, or prevent disease, helping us to lead healthier and happier lives. But there are also lots of illegal, harmful drugs that people take to help them feel good or have a good time.

Drugs are chemicals or substances that change the way our bodies work. When you put them into your body (often by swallowing, inhaling, or injecting them), drugs find their way into your bloodstream and are transported to parts of your body, such as your brain. In the brain, drugs may either intensify or dull your senses, alter your sense of alertness, and sometimes decrease physical pain.

A drug may be helpful or harmful. The effects of drugs can vary depending upon the kind of drug taken, how much is taken, how often it is used, how quickly it gets to the brain, and what other drugs, food, or substances are taken at the same time. Effects can also vary based on the differences in body size, shape, and chemistry.

Although substances can feel good at first, they can ultimately do a lot of harm to the body and brain. Drinking alcohol, smoking tobacco, taking illegal drugs, and sniffing glue can all cause serious damage to the human body. Some drugs severely impair a person's ability to make healthy choices and decisions. Teens who drink, for example, are more likely to get involved in dangerous situations, such as driving under the influence or having unprotected sex.

And just as there are many kinds of drugs available, there are as many reasons for trying them or starting to use them regularly. People take drugs just for the pleasure they believe they can bring. Often it's because someone tried to convince them that drugs would make them feel good or that they'd have a better time if they took them.

Some teens believe drugs will help them think better, be more popular, stay more active, or become better athletes. Others are simply curious and figure one try won't hurt. Others want to fit in. A few use drugs to gain attention from their parents.

Many teens use drugs because they're depressed or think drugs will help them escape their problems. The truth is, drugs don't solve problems — they simply hide feelings and problems. When a drug wears off, the feelings and problems remain, or become worse. Drugs can ruin every aspect of a person's life.

VENEZUELA HYDROGRAPHY.

The Orinoco is by far the most important of the more than 1,000 rivers in the country. Flowing more than 2,500 kilometers to the Atlantic from its source in the Guiana highlands at the Brazilian border, the Orinoco is the world's eighth largest river and the largest in South America after the Amazon. Its flow varies substantially by season, with the high water level in August exceeding by as much as thirteen meters the low levels of March and April. During low water periods, the river experiences high and low tides for more than 100 kilometers upstream from Ciudad Guayana.

For most of the Orinoco's course, the gradient is slight. Downstream from its headwaters, it splits into two; one-third of its flow passes through the Brazo Casiquiare (Casiquiare Channel) into a tributary of the Amazon, and the remainder passes into the main Orinoco channel. This passageway allows vessels with shallow drafts to navigate from the lower Orinoco to the Amazon River system after unloading and reloading on either side of two falls on the Orinoco along the Colombian border.

Most of the rivers rising in the northern mountains flow southeastward to the Río Apure, a tributary of the Orinoco. From its headwater, the Apure crosses the llanos in a generally eastward direction. Few rivers flow into it from the poorly drained region south of the river and much of this area near the Colombian border is swampland.

The other major Venezuelan river is the fast-flowing Caroní, which originates in the Guiana highlands and flows northward into the Orinoco upstream from Ciudad Guyana. The Caroní is capable of producing as much hydroelectric power as any river in Latin America and has contributed significantly to the nation's electric power production. Electricity generated by the Caroní was one of the factors encouraging industrialization of the northern part of the Guiana highlands and the lower Orinoco valley.

The Lago de Maracaibo, the largest lake in Latin America, occupies the central 13,500 square kilometers of the Maracaibo lowlands. The low swampy shores of the lake and areas beneath the lake itself hold most of Venezuela's rich petroleum deposits. The lake is shallow, with an average depth of ten meters, and separated from the Caribbean by a series of islands and sandbars. In 1955 a 7.5-meter channel was cut through the sandbars to facilitate shipping between the lake and the Caribbean. The channel also allows salt water to mix with the yellowish fresh water of the lake, making the northern parts brackish and unsuited for drinking or irrigation.

VENEZUELA ELECTRICITY

In 1990 Venezuela boasted significant electricity production and even greater potential. Besides its plentiful reserves of coal, oil, and gas, Venezuela's cascading rivers provided a hydroelectric potential in excess of 60,000 megawatts (MW), only a small fraction of which had been tapped. The country's total installed capacity in electricity multiplied more than ten times in the thirty-year period from 1960 to 1990, jumping from 1,350 MW hours to over 18,000 MW hours. Actual electricity generation paralleled that trend over the same time period, spiraling to more than 52 million MW hours. During the same time period, the percentage of electric power attributed to hydroelectricity rose to about 50 percent by 1990. Thermal-based electricity declined accordingly.

The national power network encompassed both public and private utilities under the regulation of the Ministry of Energy and Mines. Four major public-sector utilities supplied over twothirds of the country's electric power, while seven private firms provided the remainder. Until the 1986 opening of the massive Guri hydroelectricity facility, the National Electricity Company (Compañía Anónima de Administración y Fomento Eléctrico--CADAFE) accounted for over 90 percent of the electric power generated by the public sector. CADAFE increased public access to electricity from roughly 30 percent in 1960 to an estimated 92 percent by 1990. The Guri hydroelectric plant, with over 10,000 MW of installed capacity (the world's fourth largest capacity), became the nation's largest single source of electricity upon its completion in 1986. The Guri Dam, located on the Río Caroní, saved the country the equivalent of 300,000 barrels of oil a year.

Venezuela consumed more electricity than any other country in Spanish-speaking Latin America. Industry consumed 53 percent of all electricity in 1988, followed by private residences (22 percent), commercial entities (13 percent), and federal and local governments (12 percent). Electric rates were highly subsidized until 1989 when the government's structural adjustment policies triggered rate increases of 30 to 65 percent, depending on usage.

The government's plans for the 1990s focused on expanding hydroelectricity output near Ciudad Guayana and reorganizing utilities along more efficient and decentralized lines. The Venezuelan Corporation of Guayana (Corporación Venezolana de Guayana--CVG) oversaw the 360-MW Macagua I plant on the Río Caroní and planned to operate Macagua II, also on the Río Caroní, which was slated to provide an additional 2,500 MW by the early to mid-1990s. In addition, preliminary engineering work on complexes at Caruachi and Tocoma began in 1989; the CVG hoped to further harness the power of the Río Caroní to produce 2,500 MW from each of these facilities. The abundant and cheap supplies of hydroelectricity near Ciudad Guayana represented a significant advantage for Venezuelan heavy industries relative to other South American nations.

EGYPTIAN PYRAMIDS.

The Egyptian pyramids are ancient pyramid shaped masonry structures located in Egypt.
There are over 100 pyramids in Egypt. Most were built as tombs for the country's Pharaohs and their consorts during the Old and Middle Kingdom periods.

The earliest known Egyptian pyramid is the Pyramid of Djoser which was built during the third dynasty. This pyramid and its surrounding complex were designed by the architect Imhotep, and are generally considered to be the world's oldest monumental structures constructed of dressed masonry.

The best known Egyptian pyramids are those found at Giza, on the outskirts of Cairo. Several of the Giza pyramids are counted among the largest structures ever built.

The Pyramid of Khufu at Giza is the largest Egyptian pyramid. It is the only one of the Seven Wonders of the Ancient World still in existence.

By the time of the early dynastic period of Egyptian history, those with sufficient means were buried in bench-like structures known as mastabas.

The first historically documented Egyptian pyramid is attributed to the architect Imhotep, who planned what Egyptologists believe to be a tomb for the pharaoh Djoser. Amenhotep is credited with being the first to conceive the notion of stacking mastabas on top of each other — creating an edifice composed of a number of "steps" that decreased in size towards its apex. The result was the Step Pyramid of Djoser — which was designed to serve as a gigantic stairway by which the soul of the deceased pharaoh could ascend to the heavens. Such was the importance of Imhotep's achievement that he was deified by later Egyptians.

The most prolific pyramid-building phase coincided with the greatest degree of absolutist pharaonic rule. It was during this time that the most famous pyramids, those near Giza, were built. Over time, as authority became less centralized, the ability and willingness to harness the resources required for construction on a massive scale decreased, and later pyramids were smaller, less well-built and often hastily constructed.

Long after the end of Egypt's own pyramid-building period, a burst of pyramid-building occurred in what is present-day Sudan, after much of Egypt came under the rule of the Kings of Napata. While Napatan rule was brief and ceased in 661 BC, the Egyptian influence made an indelible impression, and during the later Sudanese Kingdom of Meroe (approximately in the period between 300 BC–300 AD) this flowered into a full-blown pyramid-building revival, which saw more than two hundred indigenous, but Egyptian-inspired royal pyramid-tombs constructed in the vicinity of the kingdom's capital city.

BIOGRAPHY OF THE LIBERATOR SIMON BOLIVAR.

Simón Bolívar was born in Caracas, Captaincy General of Venezuela (now Venezuela). The Bolívar aristocratic bloodline derives from a small village in the Basque Country (Spain), called La Puebla de Bolívar, which is the origin of the surname. His father descended remotely from King Fernando III of Castile and Count Amedeo IV of Savoy, and came from the male line of the de Ardanza family. The Bolivars settled in Venezuela in the sixteenth century.
A portion of their wealth came from the silver and gold mines in Venezuela. However in 1632, gold was first mined, leading to further discoveries of extensive copper deposits. Towards the later 1600s, copper was exploited with the name "Cobre Caracas". These mines became the property of Simón Bolívar's family. Later in his revolutionary life, Bolivar used part of the mineral income to finance the South American revolutionary wars. Some people claim that his family grew to prominence before gaining great wealth. For example, the Caracas Cathedral, founded in 1594, has a side chapel dedicated to Simón Bolívar's family.
Following the death of his father Juan Vicente Bolívar y Ponte, 1st Marqués de San Luis, and his mother Maria de la Concepción Palacios y Blanco, he went to Spain in 1799 to complete his education. There he married Maria Teresa Rodriguez Del Toro y Alaysa in 1802, but on a brief return visit to Venezuela in 1803, she succumbed to yellow fever. Bolívar returned to Europe in 1804 and for a time was part of Napoleon's retinue.
Bolívar returned to Venezuela in 1807, and, when Napoleon made Joseph Bonaparte King of Spain and its colonies in 1808, he participated in the resistance juntas in South America. The Caracas junta declared its independence in 1810, and Bolívar was sent to Britain on a diplomatic mission.
Bolívar returned to Venezuela in 1811. In March 1812, Bolívar was forced to leave Venezuela because of an earthquake that destroyed Caracas. In July 1812, junta leader Francisco de Miranda surrendered to the Spanish, and Bolívar had to flee to Cartagena de Indias. It was during this period that Bolívar wrote his Manifiesto de Cartagena. In 1813, after acquiring a military command in New Granada under the direction of the Congress of New Granada in Tunja, he led the invasion of Venezuela on May 14. This was the beginning of the famous Admirable Campaign. He entered Mérida on May 23, where he was proclaimed as El Libertador, following the occupation of Trujillo on June 9. Six days later, on June 15, he dictated his famous Decree of War to the Death. Caracas was retaken on August 6, 1813, and Bolívar was ratified as "El Libertador", thus proclaiming the Venezuelan Second Republic. Due to the rebellion of José Tomás Boves in 1814 and the fall of the republic, he returned to New Granada, where he then commanded a Colombian nationalist force and entered Bogotá in 1814, recapturing the city from the dissenting republican forces of Cundinamarca. He intended to march into Cartagena and enlist the aid of local forces in order to capture Royalist Santa Marta. However, after a number of political and military disputes with the government of Cartagena, Bolívar fled, in 1815, to Haiti, where he befriended Alexandre Pétion, the leader of the newly independent country. Bolívar (granted sanctuary in Haiti) petitioned Pétion for aid.
I n 1817, with Haitian soldiers and vital material support (on the condition that he abolish slavery), Bolívar landed in Venezuela and captured Angostura (now Ciudad Bolívar).
A victory at the Battle of Boyacá in 1819 added New Granada to the territories free from Spanish control, and in September 7, 1821 the Gran Colombia (a federation covering much of modern Venezuela, Colombia, Panama, and Ecuador) was created, with Bolívar as president and Francisco de Paula Santander as vice president.
Further victories at the Carabobo in 1821 and Pichincha in 1822 consolidated his rule over Venezuela and Ecuador respectively. After a meeting in Guayaquil, on July 26 and July 27, 1822, with Argentine General José de San Martin, who had received the title of Protector of Peruvian Freedom, in August 1821, after having partially liberated Peru from the Spanish, Bolívar took over the task of fully liberating Peru. The Peruvian congress named him dictator of Peru, on February 10, 1824, which allowed Bolívar to completely reorganize the political and military administration. Bolívar, assisted by Antonio José de Sucre, decisively defeated the Spanish cavalry, on August 6, 1824, at Junín. Sucre destroyed the still numerically superior remnants of the Spanish forces at Ayacucho on December 9.
On August 6, 1825, at the Congress of Upper Peru, the Republic of Bolivia was created. Bolívar is thus one of the few men to have a country named after him. The constitution reflected the influence of the French and Scottish Enlightenment on Bolívar's political thought, as well as that of classical Greek and Roman authors.
Bolívar finally resigned his presidency on April 27, 1830, intending to leave the country for exile in Europe, possibly in France. He had already sent several crates (containing his belongings and his writings) ahead of him to Europe.
He died before setting sail, after a painful battle with tuberculosis on December 17, 1830, in the Quinta de San Pedro Alejandrino in Santa Marta, Gran Colombia (now Colombia).
His remains were moved from Santa Marta to Caracas in 1842, where a monument was set up for his burial in the Panteón Nacional. The 'Quinta' near Santa Marta has been preserved as a museum with numerous references to his life.

REPRODUCTIVE SYSTEM.

Human reproduction takes place as internal fertilization by sexual intercourse. During this process, the erect penis of the male is inserted into the female's vagina until the male ejaculates semen, which contains sperm, into the female's vagina. The sperm then travels through the vagina and cervix into the uterus or fallopian tubes for fertilization of the ovum.

Pelvic region of a male that contribute towards the reproductive process. The primary direct function of the male reproductive system is to provide the male gamete or spermatozoa for fertilization of the ovum.

The major reproductive organs of the male can be grouped into three categories. The first category is sperm production and storage. Production takes place in the testes which are housed in the temperature regulating scrotum, immature sperm then travel to the epididymis for development and storage. The second category is the ejaculatory fluid producing glands which include the seminal vesicles, prostate, and the vas deferens. The final category are those used for copulation, and deposition of the spermatozoa (sperm) within the female, these include the penis, urethra, vas deferens and Cowper's gland.

Pelvic region of a female that contribute towards the reproductive process. The human female reproductive system contains three main parts: the vagina, which acts as the receptacle for the male's sperm, the uterus, which holds the developing fetus, and the ovaries, which produce the female's ova. The breasts are also an important reproductive organ during the parenting stage of reproduction.

The vagina meets the outside at the vulva, which also includes the labia, clitoris and urethra; during intercourse this area is lubricated by mucus secreted by the Bartholin's glands. The vagina is attached to the uterus through the cervix, while the uterus is attached to the ovaries via the fallopian tubes. At certain intervals, typically approximately every 28 days, the ovaries release an ovum, which passes through the fallopian tube into the uterus. The lining of the uterus, called the endometrium, and unfertilized ova are shed each cycle through a process known as menstruation.

HISTORY OF THE WORLD'S LARGEST BUILDING.

BEFORE THE 19TH CENTURY.

Modern skyscrapers are built with materials such as steel, glass, reinforced concrete and granite, and routinely utilize mechanical equipment such as water pumps and elevators. Until the 19th century, buildings of over six stories were rare, as having great numbers of stairs to climb was impractical for inhabitants, and water pressure was usually insufficient to supply running water above 50 m (164 ft).

The tallest building in ancient times was the Great Pyramid of Giza in ancient Egypt, which was 146 metres (480 ft) tall and was built in the 26th century BC. Its height was not surpassed for thousands of years, possibly until the 14th century AD with the construction of the Lincoln Cathedral (though its height is disputed), which in turn was not surpassed in height until the Washington Monument in 1884. However, being uninhabited buildings, none of these buildings actually complies to the definition of a skyscraper.

High-rise apartment building already flourished in antiquity: ancient Roman insulae in Rome and other imperial cities reached up to 10 and more stories, some with more than 200 stairs. Several emperors, beginning with Augustus (r. 30 BC-14 AD), attempted to establish limits of 20-25 m for multi-story buildings, but met with only limited success. The lower floors were typically occupied by either shops or wealthy families, while the upper stories were rented out to the lower classes. Surviving Oxyrhynchus Papyri indicate that seven story buildings even existed in provincial towns, such as in 3rd century AD Hermopolis in Roman Egypt.

The skyline of many important medieval cities had large numbers of high-rise urban towers. These towers were built for defensive but also representative functions by the wealthiest families. The residential Towers of Bologna in the 12th century, for example, numbered between 80 to 100 at a time, the largest of which (known as the "Two Towers") rise to 97.2 metres (319 ft). In Florence, a law of 1251 decreed that all urban buildings should be reduced to a height of less than 26 m, the regulation immediately put into effect. Even medium-sized towns at the time such as San Gimignano are known to have featured 72 towers up to 51 m height.

The medieval Egyptian city of Fustat housed many high-rise residential buildings, which Al-Muqaddasi in the 10th century described as resembling minarets. Nasir Khusraw in the early 11th century described some of them rising up to 14 stories, with roof gardens on the top storey complete with ox-drawn water wheels for irrigating them. Cairo in the 16th century had high-rise apartment buildings where the two lower floors were for commercial and storage purposes and the multiple stories above them were rented out to tenants. An early example of a city consisting entirely of high-rise housing is the 16th-century city of Shibam in Yemen. Shibam was made up of over 500 tower houses, each one rising 5 to 11 storeys high, with each floor being an apartment occupied by a single family. The city was built in this way in order to protect it from Bedouin attacks. Shibam still has the tallest mudbrick buildings in the world, with many of them over 100 feet (30 m) high, and the tallest of them (a minaret) standing at over 175 feet (53 m).