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
---What do you think made her so upset? ---_____________ her  hometown.
#95531
A
As she missed
B
Missed
C
Because of missing
D
Missing
It was ______ creative thinking that I took the course, not to get high marks in exams.
#96171
A
developing
B
to develop
C
developed
D
to have developed
No matter how bright a talker you are, there are times when it is better ______ silent.
#91568
A
remain
B
be remaining
C
to remain
D
having remained
He smiled and waved to the crowds _______ him,
#90580
A
waited for
B
waiting for
C
waited
D
waiting