34. GWD30-Q34:

Books in European libraries last longer than books in libraries in the United States because, although the climate in Europe is fairly humid, libraries there are not subjected to the extremes of temperature and humidity that damage collections in the United States.

1. because, although the climate in Europe is fairly humid, libraries there are not subjected to the extremes of temperature and humidity that
2. because, although the climate in Europe is fairly humid, libraries there are not subject of the extremes of temperature and humidity as those that
3. because, although the climate in Europe is fairly humid, libraries there are not subjected to the extremities of temperature and humidity as
4. because the climate in Europe is fairly humid, but still libraries there are not subject of the extremes of temperature and humidity as
5. because the climate in Europe is fairly humid, but libraries there are not subjected to the extremities of temperature and humidity such as those that为什么选A

哪位大侠拿给我讲讲这个because,although...是什么用法，看起来像状语里面加状语（乱说的）。。。

B.中的is not subject of 中的subject的意思在本句中使用错误。C.extremities 使用不对。另外as 同类比较从句缺少主语。D和E 选项中 because 引导一个从句，but引导的从句无法修饰主主句。

A中 because 后边跟了一个复合句作为对本句主句的解释。because 必须和它后边所跟的复合句用逗号隔开才正确。

be subject to是固定搭配啊，怎么会出现subjected的？？？根据这一条，就可以

把A排除了啊！

有没有人解释下？