《What are the shirts made of?》PPT课件13
《What are the shirts made of?》PPT课件13第4页

①This building was built last year. ②The sick boy was taken to hospital by the police yesterday. ③These trees were planted last year. _________________________________________________ _________________________________________________ 答案: 被动语态的一般过去时需将be动词变为过去式, 即was/were。

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