40. It is obvious that lung diseases are____smoking.

living in America for over 20 years, Brother Sway saidto a reporter the other day, “I ________ done bigger things, had biggerachievements had I stayed in China.” .

_______　—He’s friendly and helpful.

The little boy wasn’t listening _______ in class, so he often missed some important parts.

The police can’t decide whether the suspect is guilty because he could prove he was________ at the time of the crime.