ists have created GM tomatoes which______ fresh for 45 days, three times as long as normal tomatoes.

What are you going to do next weekend—I _____ yet. Do you have any good ideas

Having ________ exercise every day will do great good toyour health.

ales must come up for air after several minutes, _______ a few can stay underwater for an hour or more.

What do you think of Mary— There are some things that are not easy to _____, and her carelessness is one.