I wonder why Jack always gets good marks when he does only ______ the others.
It took them about ten days to go _____ the big desert (沙漠).[ ]
Let’s go to bed. It’s ________nine thirty.[ ]
Who’s that boy reading in the garden? Is it David?— It ____________ be David. I saw him in the classroom just now.
He went to see the man who was in hospital yesterday.— ______.