— ____ do you clean the classroom?— Three times a day.
#59294
A
How long
B
How often
C
How soon
D
How many
推荐题目
My mother_________500 yuan_______the bike. 
#59162
A
paid, on
B
paid, for
C
spent, to
D
spent, in
It’s 8:30. Jeff is _________ a football match online.
#53255
A
reading
B
looking
C
looking at
D
watching
You had better finish _______ your homework.
#60057
A
do
B
doing
C
to do
D
done