Question

英文选择要求还要帮忙解释清楚。谢谢

I know Jonathan quite well and never doubt_____ he can do a good job of it.
A. whether B. that C. when D. what
How many more decades will have to pass_____scientists succeed in providing a cure for cancer?
A. when B. before C. since D. until

Answer 1

1 B doubt 只能和that连用 表示怀疑

2 B 翻译过来是还要几十年科学家才能成功的研发出对癌症的治疗办法

所以应该是在他们研制成功之前还要多少年 所以选B

当然until 也有这个意思 可是通常 是not until 连用

Answer 2

B
B