David didn't give up (）he had failed in the experiment four times.Aif Bwhile Cthough Dsince
问题描述：
David didn't give up (）he had failed in the experiment four times.Aif Bwhile Cthough Dsince
Mr.zhao is very helpful.He often helps us () we are in trouble.
A.whether B.although C.whenever D.however
急,说明理由
答
你好,同学 正确答案： 1. 选C. though 尽管 翻译：尽管大卫做实验失败了四次,但是他没有放弃. 解析：though 是尽管的意思,引导让步状语从句,其它选项与题意不符. 2. 选C. whenever 无论何时 翻译：赵老师非常乐于助...第一题中，while也有虽然的意思啊while 一般表示两者之间对比，应该是“但是”的意思，没有虽然的意思