T he r eader ’

 
 
TEST C
 
Read the following article on the HIV virus and answer the questions that follow. 
The HIV virus is not in itself deadly. The problem comes when the virus weakens and 
eventually depletes the immune system, allowing infections to take hold. It attaches itself to and 
destroys white blood cells (CD lymphocytes, also known as helper T-cells), an essential 
component of the immune system. As the virus depletes the T-cells, your body becomes 
increasingly susceptible to an array of other infections and diseases.
Currently, AIDS is incurable. There is good news, however, in the form of protease 
inhibitors, a new class of drugs that helps keep HIV in check. Protease inhibitors helped cut the 
number of U.S. AIDS deaths by almost half from 1996 to 1997. As a result, AIDS dropped from 
the eighth leading cause of death in the United States to the fourteenth. But the steep decline in 
U.S. AIDS deaths seems to be a scourge in Africa, parts of Asia, and Latin America. In fact, nine 
of every 10 cases of AIDS are in the developing world.
HIV can lie dormant for years. Although HIV infection and its progression to AIDS is 
generally a slow process, HIV can develop at an extremely variable rate; it can take less than five 
years, or as long as 15 years to progress to AIDS. The Center for Disease Control (CDC) defines 
AIDS as one of more than 20 diseases occurring in an individual with no known cause of 
decreased resistance to the disease. These diseases usually do not develop until the T-cell blood 
count drops below 200 (in healthy adults, normal T-cell blood count is 800 to 1,300).
[“New Hope for a feared disease.” Internet address: www.planetrx.com/condition.cond_detail/info/3_ 
introduction.html]
1. The article states that the HIV virus attacks 
A. AIDS. 
B. T-cells. 
C. individuals with no known cause of decreased resistance. 
2. Less than what percent of AIDS cases in the world are in the USA? 
A. 1% 
B. 9% 
C. 10%

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64 Chapter 13, Reading in the Life and Natural Sciences 
3. Dormant, as used in the passage, most nearly means
A. incompatible. 
B. incurable. 
C. inactive. 
4. According to the passage, the HIV virus
A. is harmless. 
B. is deadly. 
C. harms the immune system. 
5. Protease inhibitors 
A. slow the HIV virus. 
B. cure the HIV virus. 
C. have no effect on the HIV virus. 
 

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CHAPTER 14: Reading in Mathematics and Computer 
Sciences