Billy is fourteen years old and in ________ grade.

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When did your brother begin ________ English?

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She saw the old man ________ into the building just now.

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He felt tired, so he stopped ________ and thought,"I will stop ________ from tomorrow on."

［　　］

A．smoking, to smoke

B．to smoke, smoking

C．smoking, smoking

D．to smoke, to smoke

When he saw me on the farm, he ________ to me.

［　　］

A．stop speaking

B．stopped speaking

C．stop to speak

D．stopped to speak

Jim ________ born in America．

［　　］

John fell asleep ________ he was listening to the music

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He walked ________ fast for us ________ catch up with

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　　He could hum songs and difficult ________.

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　　A. piece of musics

　　B. pieces of musics

　　C. piece of music

　　D. pieces of music

　　What did you ________ at university?

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