两个“高一英语”单选题---高手进5、6
5、The problem is very difficult.
I’m afraid you can’t work it out now.
_____ I fail this time, I will try it again.
A：As if B：SinceC：Even if D：Though
6、Visitors_____not to smoke in the museum.
A：will requestB：request
C：are requesting D：are requested
选出答案,并解释原因
为什么不选答案D.