The cousins are alike in age，but ________ they are as different as day and night.

Mrs Brown always takes things _________ too seriously, which makes the people around her uneasy.

 The problem is not _______so easy as you think. It’s far from being settled.

Pop music is ____ an important part of society____ it has even influenced our language.

The U.S. official said North Korea --- and Iran --- should follow in the steps of Libya, which last December said it would work__________ to allow international weapons inspectors to do their work.