I’d 是I would fail?还是I had fail?

I’d 是I would fail?还是I had fail? I'd 如何区分是I could还是I would? 怎么区分I’d 是I had 还是I would but if的用法,单项选择I don't think that i sall fail.But if i_____i would try again.A.should fail B.would fail C.shall fail D.had fail I would not fail myself Never! I'd 是指I could 还是I would?I could 和I would I could 是我能.I would 是我会. i'd rather 的'd是 had还是would Even if I fail this time ,I would try again I'd bettle hit the books!这句话中的I'd 是I had I would还是 I should? I didn’t think I’d make it这里的I’d是I would还是I could的缩写? 英语I‘d到底是到底是I would 还是I had 或是两者兼有之 I'd是什么的缩写? do还是would? 英语,i don't think that i shall fail.but if( ),i would try again.i don't think that i shall fail.but if( ),i would try again.a,should fail b,would fail c,failed d,had failed答案给的a,不理解 i'd better是i had better还是i would better I'd like you to do me a favor这里i'd 是i would 还是i had what would you like...?是I’d like to ...还是I’d like... Would you like to do sth.回答是Yes,I would.还是Yes,I'd like to.还是都可以? In case I _____, I would try again.A.will fail B.would miss C.should fail D.shall miss正确答案应该选C,为什么不能选A?请说明原因,谢谢~