tohavedone
看看吧
Thenewpowerstationisreported______withinthreeyears
AtohavecompletedBtohavebeencompleted
ChavingbeencompletedDtobecompleted
请问:这个题目应该选什么呢?我选的B但错了,D是正确答案.它们应该怎么区分呢?tohavedone应该怎么用呢?为什么我选B就错了呢?