1-Coach,can i continue with the training?

题目

1-Coach,can i continue with the training?
-Sorry,you can not _____you hanue not recovered from the knee injury
A until B before C as D unless
为什么选C,求翻译加解释
2 Hot ____the night air was,we slept deeply because we were so tired the long journey
A although
B as
Cwhile
D however
为什么选B,求翻译加解释
3 Jenny was very sad over the loss of the photos she had shot at Canada,____this was a memory she especially treasured
A as B if Cwhen D where
为什么选A ,求翻译加解释

答案