Some people are worrying about the possibility ________ mobile phones could be responsible for a range of illnesses, from rashes(皮疹) to brain tumors．

Using many symbols makes ______ to put much information on a single map.

—What do you mean ________ saying “The boy is overgrowing”?— I mean that he is tall ________ his age.

He is so addicted to smoking that ______ seems to be no chance of talking him into quitting.

Please do me a favor----_____ my friend Mr. Smith to Youth Theater at 7:30 tonight.