To finish the homework, he spent four hours _______ in the study.
#97225
A
locking
B
locked
C
locked himself
D
to lock
推荐题目
 Please excuse me _______ your letter by mistake. 
#98427
A
to open
B
to have opened
C
for opening
D
in opening
I got to the office earlier that day,   the 7:30 train from Paddington
#90663
A
caught
B
to have caught
C
to catch
D
having caught