主讲教师：林斌 北京八十中学英语特级教师
开篇语
开心自测
开心自测讲解
题一：
Jack wasn’t saying anything, but the teacher smiled at him ___he had done something very clever.
A. as if B. in case C. while D. though
题二：
To show our respect, we usually have to take our gloves off ______ we are to shake hands with.
A. whichever B. whenever C. whoever D. wherever
题三：
__________all of them are strong candidates, only one will be chosen for the post.
A. Since B. While C. If D. As
题四：
