_____ you tell me how to use this digital dictionary?

Now that the sign reads, “No person ______ smoke here”, please choose a seat in the smoking area over there if you _______ smoke.

– Whose ping pong bat is this? -- I’m not sure. I think it ______be Tom’s.

In China, you _____ vote when you are 18.

I was really anxious about you. You____ home without a word.