54. This text most probably appears in ________.

　　　 A. a newspaper　　　 　 　　　　　　　　 B. a book on Chinese medicine

C. a notice　 　　　　　　 　　　　D. a tour guide book

53. By saying that “it is too early to talk of cure for a virus that is so difficult to destroy”, the author means _______.

A. scientists hope to find the cure for AIDS soon

B. scientist don’t want to talk about their cure too early

C. scientists doubt whether a cure for AIDS can soon be found

D. it’s too late to find the cure for a virus that is so difficult to destroy

52. Which of the following is NOT a function of Valproic acid?

　　　 A. To control the effects of epilepsy.　　　　　

B. To block something that helps HIV.

　　　 C. To calm down people with depression.　　

D. To improve the strength of other drugs.

51. Which is NOT true according to the passage?

A. The ancient Egyptians used columns to divide large numbers.

B. Egyptians had discovered a way to multiply large numbers quickly after the calculator or even modern math.

C. Egyptians were good at counting.

D. The ancient Egyptians were very clever.

　　　　　　　　　　　　　　　　　　　　　　　　 　　 E

Scientists say they were able to reduce the effect of the AIDS with a drug first designed to treat other conditions. AIDS damages the protection system so the body cannot fight viruses inside the body. At present, medicines can reduce HIV to levels low enough to keep people alive. But these drugs are not a cure. Small amounts of the virus still remain in human’s body. If it wakes up again, the virus can become active and begin to copy itself, so people must continue to take medicine.

A new study has been carried out on four patients. They had already taken medicine for more than two years. The researchers first improved the effect of the drug. Then they gave the patient another one, valproic acid(丙戊酸). Valproic acid is used to help epilepsy(癫痫病) patients. Some people with depression(抑郁症) also take the drug to calm themselves down.

But valproic acid has also been shown to block something that helps HIV, the AIDS virus, to hide. The patients took the medicine twice a day for three months.

Over this time, the researchers say the amount of the virus was reduced by nearly seventy-five percent in three of the four people. But the numbers returned to earlier levels when the treatment ended.

Valproic acid has some serious dangers, especially for women who will soon give birth. Doctor Margolis says more study is needed into its use against AIDS. But the scientists do say that their early finding suggests that new methods will produce a cure of HIV in the future. Some other scientists, however, say it is too early to talk of cure for a virus that is so difficult to destroy. They say a cure would have to make the patients healthy again and the virus might not hide only in the protection system.

50. From the passage, we can conclude the ancient Egyptians were ______.

A. stupid　　　　　　　 B. clever　　　　　　　 C. interesting　　　　 D. humorous

49. What does the author tell us?

A. Egyptians were good at counting.

B. Egyptians had their own way to multiply large numbers quickly.

C. Egyptians could calculate only by adding up numbers.

D. Egyptians were quick in adding up the numbers。

48. The ancient Egyptians used columns to _______ large numbers.

A. add up　　　　　　　 B. multiply　　　　　　 C. divide　　　　　　　 D. both B and C

47. The best title of the passage is “______”.

A. Cure for Head Brain Tumor　　　　　　 　 B. Patient Survives from Osteoporosis

C. Treatment for World’s Tallest Woman　 D. Excess of Growth Hormones

　　　　　　　　　　　　　　　　　　　　　 　　　　 D

Long before the calculator or even modern math, Egyptians had discovered a way to multiply large numbers quickly. Here’s how it works.

Suppose you had this problem: 13×12=? On a sheet of paper, draw a line to separate two columns. Down the column on the left, begin with the number 1. Double it and write 2 below it, then double the 2 and write 4, and so on.

Down the column on the right, write the number you are multiplying by (in this case, 12). Under the 12, double it and write 24. Then double the 24 and write the number 48 under it, and so on.

Your columns should look like this:

　　　　　　　　　　　　　　　　　　　　　　　　 1　　　　　　 12

　　　　　　　　　　　　　　　　　　　　　　　　 2　　　　　　 24

　　　　　　　　　　　　　　　　　　　　　　　　 4　　　　　　 48

　　　　　　　　　　　　　　　　　　　　　　　　 8　　　　　　 96

　　　　　　　　　　　　　　　　　　　　　　　　 16　　　　　 192

Now find the numbers in the left column that add up to the first number in the problem (in this case, 13). The numbers 1+4+8=13, so underline the numbers in the right column opposite these numbers. Add these numbers (12+48+96) together, and you will get the sum 156, which is the correct answer to the problem of multiplying 13 by 12.

Now try another example: 38×251=?

　　　　　　　　　　　　　　　　　　　　　　　　 1　　　　　　 251

　　　　　　　　　　　　　　　　　　　　　　　　 2　　　　　　 502

　　　　　　　　　　　　　　　　　　　　　　　　 4　　　　　　 1,004

　　　　　　　　　　　　　　　　　　　　　　　　 8　　　　　　 2,008

　　　　　　　　　　　　　　　　　　　　　　　　 16　　　　　 4,016

　　　　　　　　　　　　　　　　　　　　　　　　 32　　　　　 8,032

We see that 2+4+32=38. So 38×251=502+1,004+8,032. And that equals 9,538.

The ancient Egyptians also used columns like these to divide large numbers. Can you think of how they might have done that?

46. The underlined word “shrink” in the last paragraph probably means ______.

A. draw together 　　　　　　　　 B. reduce in size 　　　　　

C. move back 　　　　　　　　　　 D. stop growing

45. According to the passage, which is the best thing that Defen should do to live a normal life?　

A. Harden her bones. 　　　　　 B. Repeatedly take medicine.

C. Lie in bed all day.　　　　　　 D. Have an operation to remove the brain tumor.