could not have their meals at any time是部分否定还是完全否定?

could not have done 谁知道could not have could not have their meals at any time是部分否定还是完全否定? must not have been;could not have Could they have forgotten their class. But for their help,we ( ) the program in timeA:had not finished B:could not have finished 括号中填哪一个, Could not help but have to 初三英语语法习题,求解释_________ ,we could not have finished the work on time为什么选择 But for their help 不选was it not for their help 或者 should they offer to help .But for their help,we_____the program in time.选项：A.con not finishB.will not finishC.had not finishedD.could not have finished请给我讲的详细一点， BUT for their help,we ___the program in time.A.can not finish B.woll not finish C.had not finished D.could not have finished 该选哪一个 为什么 （选与不选的原因都说一下） Some of them___to their elder brothers or sisters when they could not do their homework. can not have visited could have visited must have visited should not have visitedcan not have visitedcould have visitedmust have visited should not have visited __we could not have finished the work on time.A should they not offer to help us B but for their help 想知道A错误在哪里,如何改.答案是B. There have always been heads of families w...here have always been heads of families who thought they could do the job better or for one reason or another preferred not to entrust their personal belongings to any commercial operation )______ any instructions from their government,they could not give an answer.　　A.Having not)______ any instructions from their government,they could not give an answer.　　A.Having not received B.Not having received 　　C.Receiving not D.Not In fact,you did not know they could have been could not could not