It must have been they who gave the signal.为什么是they而不是them呢?

It Must Have Been Love (Cologne) 歌词 It Must Have Been Love 歌词 这个句子“It Must Have Been Love”说的是什么意思? It must have been so though for you,huh? must have been done must have done must have/ must have been的区别 It must have been they who picked the flowers.这里的强调句的must have been 为什么用现在完成时? It must have been drop somewhere in the 为什么用been 英语翻译‘It must have been a formidable child,’ Rickword writes,‘who,at the age of nine,could write such a vigorous and witty condemnation of a classical education and the system of competitive examination‘ That formidable child did in th It must have been about two in the morning when I returned home .must have been 是什么语法为什么加been take a look at that car,it must have been expensive,为什么用have been?为啥不说it must be expensive? I parked my car right here but now it's gone.It ____ .A must have been stolen B must have stolenC may be stolenD must be stolen he must have done it yesteraday,――?he must have done it for 2 years ――?he must have done it yesteraday,――?he must have done it for 2 years ――?he must have been here yesterday――?he must have been here for 2 years――?这几个反 he must have done it yesteraday,――?he must have done it for 2 years ――?he must have done it yesteraday,――?he must have done it for 2 years ――?he must have been here yesterday――?he must have been here for 2 years――?这几个反 must not have been;could not have have done 和gave been done的用法last night it must have been rained为什么错 雨是被下的,所以我觉得应该用have been done. It's the frist time that I( )asleep then.A.must be B.must have been C.should be D.should have been为什么 ----Wsa that the new school master who walked by?----_______A.It must be that B.It must have been C.He must be D.This must have been为什么选B啊