T-4-Q29/OG12 6 E为什么是过完，求解释

demorgan

In late 1997, the chambers inside the pyramid of the Pharaoh Menkaure at Giza 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 fungus was growing on the walls.
A.due to moisture exhaled by tourists, which raised its humidity to such levels so that salt from the stone was crystallizing

B.due to moisture 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

because moisture exhaled by tourists had raised the humidity within them to such levels that salt from the stone was crystallizing
我选A，答案E；A错在哪儿？难道是because比due to 好？还是说A的which降格了？降格能不能用来判断正误？最重要的是我觉得E的过去完成时没有明显的时间标志，哪儿看出来是过完呢？求解释，求NN，满地打滚中。。。。。

demorgan

谢谢，其实这句话我意思不理解，只是靠技巧做的;A的which是不是错误的修饰了tourists？

dadadaxia

A错在which了，its也不对
过去完成时是因为主句动作在1977，用过去时，湿度升高在主句动作之前