It's the frist time that I( )asleep then.A.must be B.must have be_英语解答

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

人气：386 ℃　时间：2019-10-11 20:29:08

解答

B主+序数词+time that +that_分句,that 后一律用完成时当主句动词为is/will be 时,that 分句动词一律用现在完成时,引导词that 可以省略,如：it's the first time i've been here当主句动词为was 时,that 分句动词...