Boris has brains. In fact，I doubt whether anyone in the class has ____IQ.

He said he ____ an American before

It matters littlea teacher looks like butmatters much is how a teacher teaches his／her students

They look ________and they think about the problem ________.

Many experts agree that once thesetreasures are _______ to the air, great harm will be done to them. So theythink it better not to unearth the treasures.