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31．Newton was playing under an apple tree an apple fell onto his head．A．when B．while C．a(chǎn)fter D．before 【查看更多】

 

題目列表(包括答案和解析)

Newton was playing under an apple tree           an apple fell onto his head．

A．when                   B．while                   C．a(chǎn)fter                             D．before

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Newton was playing under an apple tree ________ an apple fell onto his head．

[　　]

A．when

B．while

C．after

D．before

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Newton was playing under an apple tree _____an apple fell onto his head.

A．when            B．while              C．a(chǎn)fter              D．before

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