两个英语习题~快帮忙解答!求详解

题目

两个英语习题~快帮忙解答!求详解
1.Ever since Picasso's painting went on exhibit,there__large crowds at the museum every day. A.have been B.has been C.is D.are being这个题为什么选A?有every day表每天,不是应该用一般现在时吗,为什么不选C?
2.Bob's leg got hurt__the Purple mountain. A.while he is climbing up B.whlie we were climbing up C.while we climbed up D.while he climbed up这个题为什么选B,不能选A或者D呢?

答案

1have been = There be的完成式
every day 并不是整个句子的时间状语,注意：“自从毕加索的画展出之后”.这是整个句子的时间状语.“自...之后”所以用完成时
2 while 跟进行时,发生在过去,所以用过去进行时