________is dangerous for us to swim in the river alone.

He hardly goes to school by car, _________ he?

—Tom, you never told me why you were late for school again,_____ you?        —____. But maybe you forgot it, sir.                           

 ---Tom had better stay at home, _____ he?----Yes, but he’d better ____ turn the TV on.

---You never exercise. ---_______. I walk for more than one hour every day.