关于过去将来完成时,还有非谓语动词的两道题.1.Lindawas···theexperimentamonthago,butshechangedhermindatthelastminute.A.tostartB.tohavestartedC.tobesartingD.tohavebeenstarting答案是选B,跟过去将来

Question

关于过去将来完成时,还有非谓语动词的两道题.
1.Linda was ··· the experiment a month ago,but she changed her mind at the last minute.
A.to start B.to have started C.to be sarting D.to have been starting
答案是选B,跟过去将来时有关,可是我看不懂····
2.It is not uncommon for there ···· problems of communication between the old and the young.
A.being B.would be C.be D.to be.
答案是选D.什么叫做there be 还可以做介词of,about 的宾语,用there being的形式.原谅我薄弱的语法知识.

Answer 1

1,首先这是一个虚拟句,but是个含蓄虚拟,与过去事实相反,用过去完成时.
排除法：A 时态不对,C和D都有被动的意思,主语是linda,和start的关系是主动
2,there to be 的用法
1) 用作动词的复合宾语.
　　Would you like there to be a picture on the wall?你喜欢墙壁上挂一张画吗?
2) 用在It be + adj.for...的结构中
　　It is impossible for there to be any more chance.不可能在有机会了.（这就是一种结构,记住就可以了）
there being 的用法
1) 用作介词后的复合宾语
　　I never dreamed of there being a picture on the wall.我从未想到墙壁上有幅画.
2) 作状语用的独立结构
　　There being nothing to do,we went home.因为没有什么事要办,我们就回家了.