请教OG12-6

sl44999

6、In late 1997, the chambers inside the pyramid of the Pharaoh Menkaure at Giza were were closed to visitors for cleaning and repair due to moisture exhaled by tourists,which raised its humidity to such levels so that salt from the stone was crystallizing and fugus was growing on the walls.

A. due to mositure exhaled by tourists ,which raised its humidity to such levels so that salt from the stone was crystallizing

B. due to mosture that tourists had exhaled,thereby raising its humidity to such levels that salt from the stone would crystallize

C. because tourists were exhaling moisture, which had raised the humidity within them to levels such that salt from the stone would crystallize

D. because of moisture that was exhaled by tourists raising the humidity within them to levels so high as to make the  salt from the stone crystallize

E. because moisture exhaled by tourists had raised the humidity within them to such levels that salt from the stone was crystallizing

答案是E  

答案对C和D的解释都提到了一点：the pronoun them  seems to refer  to tourists. 但是E选项中也有them为什么就对呢？

请各位讲解下，十分感谢^^

zylrt

E选项当中的them指代的是主语chambers，所以对
E选项放到句子里
In late 1997, the chambers inside the pyramid of the Pharaoh Menkaure at Giza were closed to visitors for cleaning and repair because moisture exhaled by tourists had raised the humidity within them to such levels that salt from the stone was crystallizing and fugus was growing on the walls.


粗体部分，是句子的主要结构，这样就很明了了，them指代的是主句中的chambers，所以是对的。

我是这样理解的，如有偏差，请NN指正！谢谢