He said I must have done something bad to deserve it.
他說我肯定是罪有應得。
Now, I hadn't told him these details, so he must have done some research on his own.
你看，我沒有告訴他這些細節，因此他一定是自己作了一些調查。
She must have done a lot of work on it.
她一定在這上面花了不少功夫。
Where you come from, you must have done something.
你從哪裡來的`，你一定做了什麼事。
You must have done well to have achieved this success.
你取得了這樣的成就，一定乾的錯。