2013年职称英语理工类补全短文练习题(2)

The Invader of AIDS

　　The invader is small, even in the microscopic world of bacteria and viruses. It is alive only in the strictest sense of the world. It had no intelligence, no means of mobility, no methods of defense in the outside world. It is fragile, easily killed by common household bleach(漂白剂)and even short periods outside the body. 1 . It is the AIDS virus, and it is a killer.

　　AIDS is a disease, caused by a virus that breaks down part of the body’s immune system, leaving a person defenseless against a variety of unusual life-threatening illnesses.2 . The body’s immune system normally provides us the weapons we need to win constant battles with invading viruses, bacteria and other invading organisms. His defense system is powerful but not perfect. 3 . We do not even know that anything is happening.

　　But the AIDS virus acts differently from other invaders. It attacks the very cells that normally protect us. 4 . It turns our own white blood cells into mini-factories or making more viruses. Each time a cell is taken over, it fills up with thousands of new viruses, dies and releases those viruses, with attack more white blood cells. After enough attacks, our defense system is weakened and certain infections and conditions that we normally fight off with no problem take advantage of his weakness.

　　5 . The person dies. There are no cure for AIDS, so learning about the disease and how to avoid it are our only weapons.

　　A Yet it may be the most dangerous enemy in human history

　　B Whatever condition develops because of AIDS, the outcome is always the same

　　C It gets inside these cells into mini factors or making more virus

　　D Each of the letters in AIDS stands for a word:Acquired Immune Deficiency Syndrome

　　E The patients who suffer from AIDS have characteristic features

　　F Most attacks are detected and beaten off with ease