One of the great things about science is that it has taught us to be __________ about surface appearances. The world seems flat, but it is, in fact, round.
_______ in the regulations that you shouldn't tell other people the password of your e-mail account.
The manager, _______ it clear to us that he didn't agree with us, left the meeting room.
I'm moving to the countryside because the air there is much fresher than _______ in the city.
While watching television, _______.
Only after my friend came _______.