This old computer must have been of great use to _______ did the scientific research.
A: those
B: when
C: whoever
D: whomever
A: those
B: when
C: whoever
D: whomever
举一反三
- This old computer must have been of great use to _______ did the scientific research. A: those B: when C: whoeve D: whomeve
- What did the old man say when the train startedThe old man said the other man must have（）.
- He must have been very nervous when speaking. Did you _______ that his hand was shaking?
- He did not attend the meeting yesterday. He______ill. A: must be B: must have been C: should be D: should have been
- You must have been to the Great Wall,____________?