单项选择题
A.Do B.Did C.Never D.Isn’t
（） fire doors, windows, hatches, accesses and ventilato...
单项选择题（） fire doors, windows, hatches, accesses and ventilators.
A.Closed B.Close C.Closing
Inform the bridge and give the alarm at once （）the fire...
单项选择题Inform the bridge and give the alarm at once （）the fire.
A. in case B. case of C. in case of D. in the case of
Fire and boat drills are carried out （）.A.periodicallyB...
单项选择题Fire and boat drills are carried out （）.
A.periodically B.quarterly C.monthly D.yearly
