问题补充：
Thank you for giving me a hand. I in the experiment without your valuable help.
A. have failed
B. will fail
C. would have failed
D. must have failed
答案：
A. have failed
B. will fail
(答案→)C. would have failed
D. must have failed
解析：考查含蓄条件句。该句用介词短语表达条件，即：I would have failed in the experiment without your valuable help.=I would have failed in the experiment if I hadn’t got your valuable help.如果没有你宝贵的帮助，我本会实验失败的。
