cet4虚拟语气题目求指教看到一道题目如下Shouldgreenplantsdisappearsomeday,____ontheearth..AtherewillhardlybeanylifeBtherewillbenolifeCtheremusthavebeennolifeDtherewouldhardlybeanylife但是本人不解.

　　cet4虚拟语气题目求指教

　　看到一道题目如下

　　Shouldgreenplantsdisappearsomeday,____ontheearth..

　　Atherewillhardlybeanylife

　　Btherewillbenolife

　　Ctheremusthavebeennolife

　　Dtherewouldhardlybeanylife

　　但是本人不解.觉得应该是选D求前辈指教,对此题进行具体分析!