He said I must have done something bad to deserve it.
他说我肯定是罪有应得。
Now, I hadn't told him these details, so he must have done some research on his own.
你看，我没有告诉他这些细节，因此他一定是自己作了一些调查。
She must have done a lot of work on it.
她一定在这上面花了不少功夫。
Where you come from, you must have done something.
你从哪里来的`，你一定做了什么事。
You must have done well to have achieved this success.
你取得了这样的成就，一定干的错。