问题补充:
39. Thank you for your help. for your help, I wouldn’t have succeeded in my experiment.
A. If it is not
B. Were it not
C. Had it not been
D. If they were not
答案:
A. If it is not
B. Were it not
C. Had it not been
D. If they were not
解析:可联系答.案.网客服索取。