. Please remain __________ until the plane has come to a complete stop.
#98531
A
to seat
B
to be seated
C
seating
D
seated
推荐题目
We found the baby  ____ on the floor.      
#95880
A
slept
B
sleep
C
to sleep
D
sleeping
Robert is said _______ abroad, but I don’t know what country he studied in. 
#98633
A
to have studied
B
to study
C
to be studying
D
to have been studying