I failed to pass...表示过去,为什么不能是I fail to passed?

I failed to pass...表示过去,为什么不能是I fail to passed? Susan failed to pass the exam,( 反义疑问句 He failed to pass the test反问怎么问? He failed to pass the axam,(我也） Oh,you have failed the maths exam again.______.I will work hard to pass it next timeA.so have I B.so I have failed to pass在反义疑问句中为什么用否定He failed to pass the exam 改否定句为什么用didnt he求 They failed to pass the exam last time,i regretted_____A、to be not able to helpB、being unable to helpC、being not able to helpingD、not be able to help选哪个 为什么? They failed to pass the exam last time,I regretted___.A.being unable to help B.not to be able to help请解释为什么.regret to do 和 regret doing 的区别 be not able to do sth be unable to do sth区别They failed to pass the exam last time,I regretted ___.A.being unable to helpB.being not able to help Much effort ____she had made,she still failed to pass the driving testing.（as/though） WHY?Much effort ____she had made,she still failed to pass the driving testing.（as/though） WHY?I have nothing that make it better.中的make为什么不用 fail an exam的近义词是啥?是Failed to pass the exam吗? he failed ----- the final exam A.to pass B passing请说明原因 Though he worked hard,he failed to pass the ____ exam.(enter) 单句改错 He searched for all his pockets but failed to find his pass. unluckily,i------(fail) to pass the exam. I don't suppose she could have done well in the exam last week,did she?_________,she almos failed to pass the exam.请问此处是填YES还是NO?为什么?什么是前肯后否? Tom failed ( ) (pass) the Chinese exam again. . Tom failed in the exam again __ he wanted to pass it very much. 　解释. Tom failed in the exam again __ he wanted to pass it very much.　　A. if　　B. so　　C. though　　D. as