问题 单项选择题 A1型题

免疫应答过程的三个阶段是()

A.识别、激活和效应阶段

B.激活、识别和效应阶段

C.效应、识别和激活阶段

D.识别、增殖和分化阶段

E.识别、分化和增殖阶段

答案

参考答案:A

解析:免疫应答包括三阶段:①识别阶段:抗原加工处理、呈递,T细胞、B细胞通过抗原识别受体对抗原识别过程;②激活阶段:T细胞、B细胞活化,增殖,分化过程;③效应阶段:效应细胞和效应分子发生免疫效应过程。三阶段中不包括T细胞在胸腺内分化成熟过程。

单项选择题
单项选择题

The "standard of living" of any country means the average person’s share of the goods and services which the country produces. A country’s standard of living, (1) , depends first and (2) on its capacity to produce wealth." Wealth" in this sense is not money, for we do not live on money (3) on things that money can buy. "Goods" such as food and clothing, and "services" such as transport and " (4) ". A country’s capacity to produce wealth depends upon many factors, most of (5) have an effect on one another. Wealth depends (6) a great extent upon a country’s natural resources. Some regions of the world are well supplied with coal and minerals, and have a fertile soil and a (7) climate; other regions possess none of them.

Next to natural resources (8) the ability to turn them to use. China is perhaps as well (9) as the USA in natural resources, but suffered for many years from civil and (10) wars, and (11) this and other reasons was (12) to develop her resources. (13) and stable political conditions, and (14) from foreign invasion, enable a country to develop its natural resources peacefully and steadily, and to produce more wealth than another country equally well (15) by nature but less well ordered.

A country’s standard of living does not only depend upon the wealth that is produced and consumed (16) its own borders, but also upon what is indirectly produced through international trade. (17) , Britain’s wealth in foodstuffs and other agricultural products would be much less if she had to depend only on (18) grown at home. Trade makes it possible for her surplus manufactured goods to be traded abroad for the agricultural products that would (19) be lacking. A country’s wealth is, therefore, much influenced by its manufacturing capacity, (20) that other countries can be found ready to accept its manufactures.

8()

A.comes

B.come

C.coming

D.came