All passengers ______ are expected to fasten the seat belts when the plane takes off and lands．
#27474
A
on aboard
B
on board
C
on the board
D
on boards
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— _________, this math problem seemed quite simple to me, but when I tried to work it out, I just couldn’t.— There are always things like this, I think.
#27613
A
On one hand
B
In my opinion
C
At first sight
D
On its own
If a television or radio breaks the new rules, it is forbidden to screen advertisements and the officials ______ face serious punishment.
#25557
A
in place
B
in order
C
in advance
D
in charge
Don’t forget to turn on your radio at 7 p.m. this evening. We’ll be back _______ then.
#26779
A
in the air
B
by air
C
on the air
D
off the air