I think I have tried my best.All that can be done ___.A.has done B.has been done C.had done D.had been done为什么选B不选D

I have tried 和 I tried 有什么不同 i have tried.guys,i really tried是什么意思 I think all the_____(design)have tried their best to finish the job I have just tried to ring you... I have tried the mooncakes是什么意思 I think i have lost I think you have rt I think you have sex I think you can have I think I deserve to have you I think I have poor-------(健康） I have tried my best and given my heart Have you tried it?(yes.i have just tried it.i have never tried it before)这个回答是正确的吗? OC!i tried already I tried to call I don't think so.I am very tried.的意思 i dont think about what i have done,i think about what i have contributed I have tried,but I feel that it is OK.I remember a Chinese