tom was very happy when his parents told him that they__back to america so

问题描述:

tom was very happy when his parents told him that they__back to america so
A. would come B. will come C. is comingD. are coming

首先要圈定事态,题中“was" 告诉你这事是发生在过去的,故B C D都不符合,would是will的过去式,这应该是一个过去将来时的句式,应选A.
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