单项选择题
A.has made B.make C.has been made D.is making
（）, which consisted of seven short blasts and one prolo...
单项选择题（）, which consisted of seven short blasts and one prolonged blast, all passengers have to go to their assembly station.
A.When the distress alert is sounded B.When the emergency equipment is switching on C.When the general emergency alarm is sounded D.When the distress broadcast is sounded
We have just received a message from shore（）assistance ...
单项选择题We have just received a message from shore（）assistance is on the way.
A.When B.Where C.how D.that
（）we stand away from the church bell, it takes time for...
单项选择题（）we stand away from the church bell, it takes time for the sound waves to reach us.
A.If B.Whenever C.Because D.Where
