Question

Up to now,the program ____thousands of children who would otherwise have died

A.would save
B.saves
C.had saved
D.has saved

Answer 1

这个题选C，这是虚拟语气的三种用法之一。
1.与现在事实相反的虚拟条件句，条件从句的谓语用动词的过去式 (be的过去式用were), 主句的谓语用should （would, might， could）+动词原形；
2.与过去事实相反的虚拟条件句，条件从句的谓语用had+过去分词，主句的谓语用should （ would, might， could）+ have ＋过去分词；
3.与将来事实可能相反的虚拟条件句，条件从句的谓语用动词的过去式(be的过去式用were)； should＋动词原形；were to＋动词原形，主句用should （would, might， could）+动词原形。

Answer 2

选D-“从过去到现在持续发生的动作应使用现在完成时，而且这个动作很可能继续发生”

Answer 3

Up to now,the program __had saved __thousands of children who would otherwise have died

Up to now 是到现在为止，即现在之前，是过去或。

Answer 4

D
Up to now 到现在为止
是现在完成时的标志词之一
相同的用法还有：so far …

Answer 5

D Up to now 到现在为止，和现在完成时连用。