Many people believe _______ robots will do most of our housework in the future.
#57999
A
that
B
if
C
why
D
how
推荐题目
This sign means “ _____.”
#57944
A
No parking
B
No U-turn
C
No right turn
D
No left turn
Don’t stop working _____ twelve. 
#58157
A
to
B
at
C
when
D
until