Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions.

The first two decades of this century were dominated by the microbe hunters. These hunters had tracked down one after another of the microbes responsible for the most dreaded scourges of many centuries: tuberculosis, cholera, diphtheria. But there remained some terrible diseases for which no microbe could be incriminated: scurvy, pellagra, rickets, beriberi. Then it was discovered that these diseases were caused by the lack of vitamins, a trace substance in the diet. The diseases could be prevented or cured by consuming foods that contained the vitamins. And so in the decades of the 1920's and 1930's, nutrition became a science and the vitamin hunters replaced the microbe hunters.

In the 1940's and 1950's, biochemists strived to learn why each of the vitamins was essential for health. They discovered that key enzymes in metabolism depend on one or another of the vitamins as coenzymes to perform the chemistry that provides cells with energy for growth and function. Now, these enzyme hunters occupied center stage.

You are aware that the enzyme hunters have been replaced by a new breed of hunters who are tracking genes - the blueprints for each of the enzymes - and are discovering the defective genes that cause inherited diseases - diabetes, cystic fibrosis. These gene hunters, or genetic engineers, use recombinant DNA technology to identify and clone genes and introduce them into bacterial cells and plants to create factories for the massive production of hormones and vaccines for medicine and for better crops for agriculture. Biotechnology has become a multibilliondollar industry.

In view of the inexorable progress in science, we can expect that the gene hunters will be replaced in the spotlight. When and by whom? Which kind of hunter will dominate the scene in the last decade of our waning century and in the early decades of the next? I wonder whether the hunters who will occupy the spotlight will be neurobiologists who apply the techniques of the enzyme and gene hunters to the funtions of the brain. What to call them? The head hunters. I will return to them later.
Question:How do vitamins influence health?

A. They protect the body from microbes

B. They are broken down by cells to produce energy

C. They keep food from spoiling

D. They are necessary for some enzymes to function

Children in Vietnam and England have to take the ______ at the end of their secondary education.

A. semester 

B. state school       

C. GCSE examination    

D. education system

Cho hai cấp số nhân có cùng số các số hạng. Tích các số hạng tương ứng của chúng có lập thành cấp số nhân không? Vì sao? Cho một ví dụ minh họa.

Thành phần % khối lượng của nitơ trong hợp chất hữu cơ C x H y N  là 23,73%. Số đồng phân amin bậc một thỏa mãn các dữ kiện trên là:

A. 2.

B. 3.

C. 4.

D. 1.

Cho 0,1 mol CH 3 COOH  vào cốc chứa 30 ml dung dịch ROH 20% (d =1,2 g/ml, R là một kim loại kiềm). Cô cạn dung dịch sau phản ứng rồi đốt cháy hoàn toàn chất rắn khan thì thu được 9,54 gam chất rắn và có m gam hỗn hợp gồm CO 2 , hơi nước bay ra. Giá trị của m là :

A. 10,02

B. 9,3

C. 7,54

D. 8,26

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the  correct answer to each of the questions from 43 to 50.

          Langston Hughes was one of the greatest American writers of the twentieth century. He was born in Joplin, Missouri, and moved to Cleveland at the age of fourteen. Four years later he went to Mexico and spent one year there before attending Columbia University in New York. For a few years after that he roamed the world as a seaman, visiting ports around the world and writing some poetry. He returned to the United States and attended Lincoln University, where he won the Writer Bynner Prize for undergraduate poetry. After graduating in 1928, he traveled to Spain and to Russia. His best novels include “Not Without Laughter” and “The Big Sea”. He wrote an autobiography in 1956 and also published his collections of poetry then. A man of many talents, Hughes is one of the most accomplished writers in American literature history.

When did he travel to Spain?

A. in 1956

B. in 1928

C. in 1958

D. in 1960

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 43 to 50.

 After the United States purchased Louisiana from France and made it their newest territory in 1803, President Thomas Jefferson called for an expedition to investigate the land the United States had bought for $15 million. Jefferson’s secretary, Meriwether Lewis, a woodsman and a hunter from childhood, persuaded the president to let him lead this expedition. Lewis recruited Army officer William Clark to be his co-commander. The Lewis and Clark expedition led the two young explorers to discover a new natural wealth of variety and abundance about which they would return to tell the world.

 When Lewis and Clark departed from St. Louis in 1804, they had twenty-nine in their party, including a few Frenchmen and several men from Kentucky who were well-known frontiersmen. Along the way, they picked up an interpreter named Toussant Charbonneau and his Native American wife, Sacajawea, the Shoshoni “Bird Woman” who aided them as guide and peacemaker and later became an American legend.

 The expedition followed the Missouri River to its source, made a long portage overland though the Rocky Mountains, and descended the Columbia River to the Pacific Ocean. On the journey, they encountered peaceful Otos, whom they befriended, and hostile Teton Sioux, who demanded tribute from all traders. They also met Shoshoni, who welcomed their little sister Sacajawea, who had been abducted as a child by the Mandans. They discovered a paradise full of giant buffalo herds and elk and antelope so innocent of human contact that they tamely approached the men. The explorers also found a hell blighted by mosquitoes and winters harsher than anyone could reasonably hope to survive. They became desperately lost, then found their way again. Lewis and Clark kept detailed journals of the expedition, cataloging a dazzling array of new plants and animals, and even unearthing the bones of a forty-five-foot dinosaur.

 When the party returned to St. Louis in 1806 after travelling almost 8,000 miles, they were eagerly greeted and grandly entertained. Their glowing descriptions of this vast new West provided a boon to the westward migration now becoming a permanent part of American life. The journals written by Lewis and Clark are still widely read today.

Lewis and Clark encountered all of the following EXCEPT_______.

A. mountains

B. buffaloes

C. dinosaur herds

D. friendly people

Read the following passage and mark the letter A, B, C or D on your answer sheet to choose the best answer for each of the question from 43- 50

Staggering tasks confronted the people of the United States, North and South when the Civil War ended. About a million and a half soldiers from both sides had to be demobilized, readjusted to civilian life, and reabsorbed by the devastated economy.

Civil government also had to be put back on a peacetime basis and interference from the military had to be stopped. The desperate plight of the South has eclipsed the fact that reconstruction had to be undertaken also in the North, though less spectacularly. Industries had to adjust to peacetime conditions; factories had to be retooled for civilian needs.

Financial problems loomed large in both the North and the South. The national debt had shot up from a modest $65 million in 1861, the year the war started, to nearly $3 billion in 1865, the year the war ended. This was a colossal sum for those days but one that a prudent government could pay. At the same time, war taxes had to be reduced to less burdensome levels.

Physical devastation caused by invading armies, chiefly in the South and border states, had to be repaired. This Herculean task was ultimately completed, but with discouraging slowness.

Other important questions needed answering. What would be the future of the four million Black people who were freed from slavery? On what basis were the Southern states to be brought back into the Union?

What of the Southern leaders, all of whom were liable to charges of treason? One of these leaders, Jefferson Davis, president of the Southern Confederacy, was the subject of an insulting popular Northern song, “Hang Jeff Davis from a Sour Apple Tree,” and even children sang it. Davis was temporarily chained in his prison cell during the early days of his two-year imprisonment. But he and the other Southern leaders were finally released, partly because it was unlikely that a jury from Virginia, a Southern Confederate state, would convict them. All the leaders were finally pardoned by President Johnson in 1868 in an effort to help reconstruction efforts proceed with as little bitterness as possible.

According to the passage, which of the following statements about the damage in the South is correct?

A. It was worse than in the North

B. The cost was less than expected 

C. It was centered in the border states

D. It was remedied rather quickly

Traditionally in Vietnam, the wedding ceremony starts in front of the ______.

A. house    

B. guests     

C. altar        

D. church

Tìm các số hạng của cấp số nhân u n có năm số hạng, biết:  u 4   –   u 2   =   25 và u 3   –   u 1   =   50