The policeman came up to the house, whose door was open, _____ there for a while, and went in.
#100895
A
to stand
B
standing
C
stood
D
stand
推荐题目
Large quantities of oil      in a place near my hometown recently. 
#102718
A
has discovered
B
have discovered
C
has been discovered
D
have been discovered
It is most instructive lecture that I _______ since I came to this school.
#101499
A
attended
B
had attended
C
am attending
D
have attended
 -I haven't heard from Henry for a long time. -What do you think ________ to him? 
#104036
A
happening
B
to happen
C
has happened
D
had happened
Great changes __________ in this city over the past five years.
#101001
A
took place
B
have been taken place
C
were taken place
D
have taken place