—Why does        take Tom an hour to get home?— I don’t know. Maybe the traffic is heavy.

 —Is this your baseball, David?   —No, it's not     . It's Helen's.

–Does your sister like red?–Yes. This red skirt belongs to ______.

—What could I get my father for Father’s Day? — _____getting him a tie?

 Things are ________ on Mars ________ on Earth because of the different gravity.