新概念英语3的几个选择题不懂,求讲解.

新概念英语3的几个选择题不懂,求讲解.Anthropology is a science ____ anthropologists use a rigorous set of methods and techniques to document observations that can be checked by others.A.in that B.that inC.that D.in（为什么不是C而是B?麻烦分析下句子）Merurydiffers from other industrial metals ____ it is a liquid.A.whereas B.in thatC.because of D.consequently(引导原因状语从句的这几个词分不太清,麻烦讲一下ABD项的区别.还有,那个in consequence of用法是不是相当于because of额?)She did not want to go Africa,chiefly ____ the weather is too hot.A.Because B.As C.Since D.For(答案选A,为什么?为什么不是B、C?)____we are all here,the meeting can begin.A.With B.In that C.For D.seeing(为什么选D而是不B?)