Doctors failed to save the old man’s life.句子分析

Doctors failed to save the old man’s life.句子分析 turn to doctors for The doctors tried their best ____ the dying boy's life,but they failed at last A.to save B.saveC.saving The doctors tried their best to save the patient's life,＿＿failed.A.or B.so C.but D.because The doctors did everything they-----save the---old woman but failed.A could;dead B could to;dead C could;dying D could to;dying前者为什么选could to?could后为什么加to?to 在这里的用法? Failed to read input Failed to read inpat failed to initialize title failed to create ID failed to go failed to delive是什么意思? FAILED TO AUTHENTICATE ourselves to failed to connect to server failed to connect to host Failed to connect to driver 谁帮我看看这些英文什么意思?System has failed to prevent an illegal program to be executed.Please restart your SA and try again later.我玩的是美服突袭`游戏更新完就出现这个对话框` failed to create IDispatch是什么意思 Failed to read DVD information