（）that a good student like him should have made such a big mistake.

（）by a crowd of people，he felt nervous，（）what to say.

A.Watching；didn’t know
B.Having watched；and not know
C.Having been watched；not known
D.Being watched；not knowing

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（）is no doubt that he will come here some day，but （）is doubtful when he will come.

A.There；there
B.It；it
C.There；it
D.It；there

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