GWD-13-Q32 完全看不懂得说，急！

GWD-13-Q32*:

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. (C)

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

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.

大概意思：M是种细胞，当老鼠和其他哺乳动物的免疫系统回应外部入侵组织（比如细菌）的时候，其扮演了重要的角色。但是，对于那种不能产生这种细胞的老鼠来说，当有细菌入侵时，无法出现N物质的增多。

这样就可以推出：M细胞要么可以产生N，要么可以阻止N分解。

大概意思：M是种细胞，当老鼠和其他哺乳动物的免疫系统回应外部入侵组织（比如细菌）的时候，其扮演了重要的角色。但是，对于那种不能产生这种细胞的老鼠来说，当有细菌入侵时，无法出现N物质的增多。

这样就可以推出：M细胞要么可以产生N，要么可以阻止N分解。

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