GWD-13-32

meckychen

T-3-Q23. GWD-13-32




Macrophages are cells that play a role in the response of the immune system of mice and other mammals to invasive organisms such as bacteria.  Unlike other mice, mice that are genetically incapable of making these particular cells do not show elevated levels of nitrates when infected with bacteria.



The statements above, if true, provide the most support for which of the following conclusions?



A.    Mice that are unable either to make macrophages or to make them in sufficient numbers will protect themselves from bacterial infections in some other way.

B.    Mice that show elevated levels of nitrates can easily fight off most types of bacterial infections.

C.    In mice, macrophages play a role in the production of nitrates or inhibit a process by which nitrates are broken down or otherwise eliminated.

D.   When a healthy mouse becomes infected with an invasive organism, the number of macrophages in the mouse’s body decreases.

E.    Injections of nitrates into mice that lack macrophages will not enhance the ability of these animals’ immune systems to fight off infection.

答案是C，为什么B不对呢？

meckychen

自己顶一下

cuteyb

我的想法是: 题目说 M是种细胞，在老鼠和其他哺乳动物的免疫系统内扮演回应角色，当抵御细菌侵害时。不能产生这种细胞的老鼠但感染细菌时，没有显示出N的升高。B 说显示出N升高的老鼠 能轻易抵御细菌侵害。而原文根本没说谁能抵御细菌侵害，只说了遇到细菌侵害时会有反应。 C说 M能生产N,或者组织N被分解或被消除。刚好把文章的两句话联系起来。

TheAssembly

仅仅是一个免疫系统的RESPONSE，不能说明马上能发挥效用而轻易地搞定病菌。
考的是差异性概念。

crown48

THX