[单项选择]The immune system is the body’s defender. It identifies, tracks down, and destroys troublemakers before they can hurt the body. Those troublemakers may be, for example, bacteria from a cut or splinter, a measles germ, a cold bug, or even a cancer cell.
These invaders try to take over our tissues and feed off our bodies’ nutrients. If they succeed, we become sick or, sometimes, even die. It’s the job of our immune systems to destroy these invaders before they destroy us.
Say you picked up a flu virus last week. Perhaps it entered your body through a cut, from a drinking glass, or from the air you breathe. Of course, you didn’t feel it, but the virus made its way into your bloodstream. As soon as it entered your body, it began to reproduce. Viruses have only one goal: to take over your cells. Once inside your body, viruses try to enter cells and disrupt their normal work. If left alone, these viruses would hurt so many cells that you would weaken, or worse, get a serious il
A. Cancer cells and transplants．
B. Thymus and lymphocytes．
C. Thymus and germs．
D. Healthy cells and hi曲blood pressur

[单项选择]The immune system is the body’s defender. It identifies, tracks down, and destroys troublemakers before they can hurt the body. Those troublemakers may be, for example, bacteria from a cut or splinter, a measles germ, a cold bug, or even a cancer cell.
These invaders try to take over our tissues and feed off our bodies’ nutrients. If they succeed, we become sick or, sometimes, even die. It’s the job of our immune systems to destroy these invaders before they destroy us.
Say you picked up a flu virus last week. Perhaps it entered your body through a cut, from a drinking glass, or from the air you breathe. Of course, you didn’t feel it, but the virus made its way into your bloodstream. As soon as it entered your body, it began to reproduce. Viruses have only one goal: to take over your cells. Once inside your body, viruses try to enter cells and disrupt their normal work. If left alone, these viruses would hurt so many cells that you would weaken, or worse, get a serious il
A. To take over our tissues and feed off our bodies’ nutrients.
B. To prevent bacteria or germs from entering the body.
C. To destroy the troublemakers in order that they might not hurt the body.
D. To fight against T cells.

[单项选择]

The immune system is equal in complexity to the combined intricacies of the brain and nervous system. The success of the immune system in defending the body relies on a dynamic regulatory communication network consisting of millions and millions of cells. Organized into sets and subsets,these cells pass information back and forth like clouds of bees flying around a hive (蜂巢). The result is a sensitive system of checks and balances that produces an immune response that is prompt, appropriate effective, and self-limiting.
At the heart of the immune system is the ability to distinguish between self and no self. When immune defenders encounter cells or organisms carrying foreign or nonself molecules,the immune troops move quickly to eliminate the intruders(入侵者). Virtually every body cell carries distinctive molecules that identify it as self. The body’s immune defenses do not normally attack tissues
A. The immune system’s memory.
B. Immune troops eliminating intruders.
C. Bees flying around a hive.
D. A sea of microbes.

[单项选择]
Eating potatoes is not only good for bowel health, but also for the whole immune system, especially when they come in the form of a potato salad or eaten cold. In a study on an animal model, researchers in Spain found that pigs fed large quantities of raw potato starch (RPS) not only had a healthier bowel, but also decreased levels of white blood cells, such as leucocytes and lymphocytes in their blood. White blood cells are produced as a result of inflammation or disease, generally when the body is challenged.
The general down-regulation of leucocytes observed by the Spanish researchers suggests an overall beneficial effect, a generally more healthy body. The reduction in leucocyte levels was about 15 percent. Lower lymphocyte levels are also indicative of reduced levels of inflammation, but the observed reduction in both lymphocyte density and lymphocyte apoptosis is surprising.

A. Potato soup.
B. Potato cake.
C. Potato salad.
D. Hot boiled potato.

[填空题]The specific molecules that the immune system cells produce have been purified and sequenced.

[单项选择]The immune system is equal in complexity to the combined intricacies of the brain and nervous system. The success of the immune system in defending the body relies on a dynamic regulatory communications network consisting of millions and millions of cells. Organized into sets and subsets, these cells pass information back and forth like clouds of bees swarming around a hive. The result is a sensitive system of checks and balances that produces an immune response that is prompt, appropriate, effective and self-limiting. 　　At the heart of the immune system is the ability to distinguish between self and non-self. When immune defenders encounter cells or organisms carrying foreign or non-self molecules, the immune troops move quickly to eliminate the invaders. Virtually every body cell carries distinctive molecules that identify it as self. The body’’s immune defenses do not normally attack tissues that carry a self marker. Rather, immune cells and other body cells coexist peaceably in a
A. recognize and reject all alien molecules that enter the body.
B. remove all the substances that invade the body organisms.
C. defend the body from attacks of different viruses or bacteria.
D. identify and specify all non-self molecules it encounters.