On many trains and buses, there are some special seats ________ out for senior citizens. 
#92562
A
marking
B
marked
C
to mark
D
mark
推荐题目
I'm afraid that I can't make myself _______ because of my poor English.
#91275
A
understand
B
understanding
C
to understand
D
understood
________ the past,our life is much better.
#89122
A
Comparing with
B
Be compared
C
To compare with
D
Compared with