The old man __________ in Tibet for two years as a volunteer teacher;it is an experience he  often mentions.
#101367
A
served
B
serves
C
is serving
D
has served
推荐题目
With more forests being destroyed, huge quantities of good earth      each year.
#102348
A
is washing away
B
is being washed away
C
are washing away
D
are being washed away
 ---I don't suppose the police know who did it. ---Well, surprisingly they do. A man has been arrested and ____ now.
#99645
A
has been questioned
B
is being questioned
C
is questioning
D
has questioned
—I'd like a pen which ________ well.—Will this one ________?
#99569
A
writes;do
B
writes;work
C
is written;do
D
is written;work