Itisbelievedtooverbysandstorms

It is believed to _____ over by sandstorms from AD 200 to AD 400.

A．gradually cover	B．be gradually being covered
C．have been gradually covered	D．be gradually covered

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Both sides are determined to get what they want，and there seems to be no possibility of________.

A．competence	B．composition
C．competition	D．Compromise

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After he got in touch with the Red Cross, Mr. Green ______ helping homeless women and children to a safe place.

A．set out	B．set about
C．set off	D．set down

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My computer is out of _________ order all of a sudden. Could you do me________ favor and type the plan for me right now?

A．the; a

B．the; 不填

C．不填; a

D．不填; 不填

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— Why are your hands that dirty?
— Oh, I______ in the garden since we finished breakfast.

A．worked	B．was working
C．am working	D．have been working

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Yesterday I went to see him, _________ that he had gone abroad two days before.

A．only to learn	B．to learn only
C．only learned	D．only learning

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