题目选项分析

Books in European libraries last longer than books in libraries in the United States 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 damage collections in the United States.

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.