1.This theory is rather difficult ___.I do not understand it.

题目

1.This theory is rather difficult ___.I do not understand it.
A.to explain.B.to be explain
2.They drove to the seaside for the holiday,with the project they were in charge of____.
A.finished.B.finshing.C.to finish.D.being finished
第一个我觉得不应该用被动么,为什么答案给的是A啊?
第二个我记得in charge of后面不是加动名词么,主语是人也不应该用被动啊,我觉得可能是句子结构的问题,可是我看不太明白,

答案

第一题是一个句式,用主动表被动,记住这一类的结构吧
第二题句意是,他们完成了他们负责的项目,所以他们开车去海边度假了
they were in charge of 是the project 的定语,主干是with the project finished