I()to my brother since last summmerAdidn't B hadn't writter C haven't written Ddon't writeLIPing will visit the Great Wall as soon as he()freeAwill be Bis C was D has beenOne day when I()the post office I()my unlce A pass,say B was passing,saw Cpassed,was seeing D am passing,an seeingHe()he()some mistekes in the test Asaid,will makeBsaid made Csaid,had madeDsaid,make

问题描述:

I()to my brother since last summmerAdidn't B hadn't writter C haven't written Ddon't write
LIPing will visit the Great Wall as soon as he()freeAwill be Bis C was D has been
One day when I()the post office I()my unlce A pass,say B was passing,saw Cpassed,was seeing D am passing,an seeing
He()he()some mistekes in the test Asaid,will makeBsaid made Csaid,had madeDsaid,make

C 从过去开始,直到现在,将来也可能继续.因此用现在完成时.
B is 用一般是表将来.
B过去进行的事,短暂的用一般过去,
C两个过去式,先后问题