English is difficult________ Nobody canlearn to use it in a few minutes

There is little doubt in your mind that he is innocent, ? (2012江苏)

Are you pleased with what he has done?— Not in the least. It couldn’t be __________.

The question that puzzled them is ____ they can getrid of the air pollution in the area.

You used to wear T-shirts and jeans, didn’t you— ________.