[单项选择]

Text 2
When a disease of epidemic proportions rips into the populace, scientists immediately get to work, trying to locate the source of the affliction and find ways to combat it. Oftentimes, success is achieved, as medical science is able to isolate the ,parasite, germ or cell that causes the problem and finds ways to effectively kill or contain it. In the most serious of cases, in which the entire population of a region or country may be at grave risk, it is deemed necessary to protect the entire population through vaccination, so as to safeguard lives and ensure that the disease will not spread.
The process of vaccination allows the patient’ s body to develop immunity to the virus or disease so that, if it is encountered, one can fight it off naturally. To accomplish this, a small weak or dead strain of the disease is actually injected into the patient in a controlled environment, so that his body’s immune system can learn to fight the invade
A. By training the immune system to fight weaker versions of the disease.
B. By passing information on how to fight the disease to the immune system.
C. By weakening the disease so that the immune system can defeat it.
D. Introducing the disease to the body, so that survivors have already fought it.

Text 2
When a disease of epidemic proportions rips into the populace, scientists immediately get to work, trying to locate the source of the affliction and find ways to combat it. Oftentimes, success is achieved, as medical science is able to isolate the ,parasite, germ or cell that causes the problem and finds ways to effectively kill or contain it. In the most serious of cases, in which the entire population of a region or country may be at grave risk, it is deemed necessary to protect the entire population through vaccination, so as to safeguard lives and ensure that the disease will not spread.
The process of vaccination allows the patient’ s body to develop immunity to the virus or disease so that, if it is encountered, one can fight it off naturally. To accomplish this, a small weak or dead strain of the disease is actually injected into the patient in a controlled environment, so that his body’s immune system can learn to fight the invade
A. The Smallpox Vaccine: An Analysis
B. How Vaccines Work
C. Vaccines: Methods and Implications
D. A Warning on the Negative Side Effects of Vaccines

When a disease of epidemic proportions threatens the public, scientists immediately get to work, trying to locate the source of affliction and find ways to combat. Vaccination is one of the effective ways to protect the (1) population of a region or country which may be
(2) grave risk. The process of vaccination allows the patient’s body to (3) immunity to the virus or disease so that, if it is encountered, one can fight it (4) naturally. To accomplish this, a small weak or dead (5) of the disease is actually injected into the patient in a controlled environment, (6) his body’s immune system can learn to fight the invader (7) . Information (8) how to penetrate the disease’s defenses is (9) to all elements of the patient’s immune system in a process that occurs naturally, in which genetic information is passed from cell to cell. This makes sure that (10) the patient later come int
A. so
B. too
C. rather
D. quite