问题描述：
be supposed to be done 和be supposed to have been done的区别
原句The metal bar was supposed _____to the right size
应填be supposed to be cut down
他说:当be supposed to...的主语是“物”时,它表示“本应；本该”,用于表示“某事本应该发生而没有发生”
而be supposed to后面接“have + 过去分词”时,表示“本应该做某事而没做”
这两者有区别吗?
原句The metal bar was supposed _____to the right size
应填be supposed to be cut down
他说:当be supposed to...的主语是“物”时,它表示“本应；本该”,用于表示“某事本应该发生而没有发生”
而be supposed to后面接“have + 过去分词”时,表示“本应该做某事而没做”
这两者有区别吗?
问题解答：
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