It would have saved Harriet endless grief had she now told him the truth.中的had是什么意思啊?

Should it rain,the crops _____.A.would be saved B.would have been saved C.will be saved D.had been saved选什么呢?为什么呢? It would have saved Harriet endless grief had she now told him the truth ,but she couldn`t do that. It would have saved Harriet endless grief had she now told him the truth.中的had是什么意思啊? if it should rain, the plant would be saved.这里saved为什么要用过去式吖? 虚拟语气的练习题Should it rain,the crops _____ .A.would be saved B.would have been saved C.will be saved D.had been saved 这题为什么选A?should可以表示“万一”,那么下雨就可能是真实条件,为什么不选C呢?庄家能被 Should it rain,the crops_______.A would be saved B would have been saved C will be saved虚拟中,此类句式应该是 If +主语+should/were to,主语+would/will 其中,should do 表示万一,were to 表示完全不可能,would与will可以替换, Up to now,the program ____thousands of children who would otherwise have diedA.would save B.savesC.had saved D.has saved much labour would have been saved if the electronic computers had invented before the program has saved thousands of children who would otherwise have died.otherwise的意思 i didn't know anything about the computer program,or a huge amount of time and energy ___________A would have been saved B had been saved C has been saved D will be saved As luck would have it, As fate would have it. 一道高中英语句子,请问啥意思.should it rain ,the crops would be saved. You have saved my life;I shall never forget it.为什么用have不用had? if it---,the crops would be saved.A rains B would rain C should rain D rain 选择题Up to now,the program(had saved)thousands of children who would otherwise have died.Up to now,the program______thousands of children who would otherwise have died.C.had savedD.has saved正确答案C为什么? Had I known about this computer program,a huge amount of time and energy （would have been saved）为什么不是 would have saved 有什么区别吗 能否详细讲讲 Should it rain,the crops would be saved.=Were it to rain,the crops would be saved.这个句子有没有错误啊?不是应该还原If吗?最好全面点