__________at the door before you enter the office，or you’ll be considered impolite
#65893
A
Knocking
B
Knocked
C
Knock
D
To knock
推荐题目
—I have to be at the office by noon tomorrow. My co-workers are taking me out for a final good-bye lunch. — ________ Where are you going to eat? —I don’t know. They want to treat me.
#66168
A
I don’t know.
B
How nice!
C
It’s my pleasure.
D
It’s none of my business.
—________ listen to music in class. —Sorry, I won’t do it again.
#59435
A
Let’s
B
Don’t
C
Please
D
Why not
_______it is to jump out of an airplane at 10,000 feet!
#66146
A
What an exciting experience
B
How exciting experience
C
How an exciting experience
D
What exciting experience
I know one of the things _____I was unsure about was _____ hard it would be to climb this mountain.
#65979
A
that; how
B
what; how
C
which; what
D
/; what
-Can you help me? -Yes， your teacher’s advice，in my opinion，and everything will be OK．
#66113
A
Follow
B
Following
C
If you follow
D
Followed