must have been

基本解释

He must have been so exhausted from impressing her that when she finally gave in, he gave out.
他一定为了给她留下深刻印象而用尽全力，当她最终妥协的时候，他却筋疲力尽。
If a man of Darwin's genius could not have come up a more convincing solution than that, some key factor must have been missing from the narrative.
如果天赋如达尔文的人都想不出比这更令人信服的答案，那么一定是人类进化中某个关键因素未能找到。
On another photo of two relatives asleep in chairs after Thanksgiving dinner, my Dad left a voice comment in which he joked about how exciting the dinner must have been.
另外一张照片是我的两个亲戚在感恩节晚餐后坐在椅子上睡着的情形，我爸爸在语音评论里开玩笑称晚餐时他们一定玩疯了。

But what I do remember was, at the end of that long, continuous coverage it must have been about two a.m.
He's earned the right to treat himself to this absolutely lovely -what must have been an extraordinary amount of fun to write -lovely catalog of flowers.
他已经得到了游荡的可爱之处,写这些一定会特别有趣,可爱的花丛中的权力。
耶鲁公开课 - 弥尔顿课程节选
So, you must imagine these are successive kings who are being buried in this, what must have been, sacred soil.
因此,你必须设想他们是被埋葬在,这块圣土中的历任国王
耶鲁公开课 - 古希腊历史简介课程节选

The law or state policy must have been adopted with a neutral or non-religious purpose.
FORBES: North Carolina Lawmakers Introduce Law To Establish An Official State Religion