25.Up to now,the program ________ thousands of children who would otherwise have died.

题目

25.Up to now,the program ________ thousands of children who would otherwise have died.
A.would save B.saves C.had saved D.has saved
26.Your house is always so neat—how do you ______ it with three children?
A.manage B.serve C.adapt D.construct
27.Helping others is a habit,_______ you can learn even at an early age.
A.it B.that C.what D.one
30.Drunk driving,which was once a occurrence,is now under control.
A.general B.frequent C.normal D.particular
正确答案是:DADB
我选的是:CCCD
只有答案没有解析,所以把题目发上来,请老师解析一下,

答案

D
up to now是迄今为止,说明动作从过去持续到现在,用现在完成时,而过去完成时表示的动作从过去的过去持续到过去,或者表示过去的过去发生的动作,用在这里不合适,除非把这句话变为间接引语,主句的时态为过去时：
She said that the program had saved thousands of children who would otherwise have died up to then.
A
manage这里的意思是管理,而adapt是使适应.
D
what是缩合连接代词,不是关系代词,不能引导定语从句,这里没有适当的关系代词供选择,只有一个代词one,one在这里是代替habit,作它的同位语,在one的后面跟了一句定语从句,由于关系代词在从句中作learn的宾语,所以省略,出现了这样一种结构.
B
frequent是经常的,醉驾过去是经常发生的,particular是特定的,特别的.这道题目选择B.希望我能帮助你解疑释惑.