______ your hand over your mouth when you cough. 
#66193
A
Put
B
Putting
C
To put
D
To be putting
推荐题目
—I’m leaving now.—______ you turn off the lights and the computer.
#59419
A
To make sure
B
Make sure
C
Made sure
D
Making sure
_________ it is to have a picnic ! 
#66058
A
What a fun
B
How fun
C
What fun
D
How a fun