__ is really hard __ them to climb Mount Tai. 
#69186
A
This, to
B
It, to
C
This, for
D
It, for
推荐题目
Ann has a new Iphone 4s, ______?
#69695
A
does she
B
has she
C
doesn’t she
D
isn’t she
The book cost you 50 yuan, _______?
#69450
A
doesn’t it
B
did it
C
does it
D
didn’t it
—Will you please _______ the flowers?  —Sorry. I won’t. 
#71089
A
pick
B
don’t pick
C
not to pick
D
not pick