he ____ smoke when he was very young.A.used to B.likes to C.\ D.had

he ____ smoke when he was very young.A.used to B.likes to C.\ D.had

这句话中,when后面的句子是说的过去,所以主句也要用过去式,就排除了B和D,had后面用smoke,smoke不能是原形,就只有选A.
used to 过去常常
原句的意思是：当他年轻的时候,他常常抽烟.
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