Our professor told us that salt water _____ at a lower temperature than fresh water.

Rather than _____on a crowded bus, he always prefers _____a bicycle.

________I know，Mike has no interest in the novel you wrote.

Smoking, ____ some smokers, might ease their anxiety sometimes, but ____ the addiction caused by their constant practice, it is really hard to give up.

All the passengers were ______ of the flight which was put off because of heavy fog.