第1个回答 2022-07-25
must have done肯定已经做……。表示对过去的或已发生的事情的判断。(现在已经不了)
He must have done a good job.
must have been doing肯定一直做……。表示对一直发生的动作的判断。现在可能还在发生中。
John must have been playing football and Mary (must have been) doing her homework.
约翰一定在踢球,而玛丽一定在做作业。
The car must have been doing at least 100 miles an hour.
这车速肯定每小时至少100英里。
《牛津词典》