Our teacher often tells us________in the river. It's dangerous.( )
not swim
not to swim
to swim
swimming
I’ll go to visit my uncle in England ________ the winter holidays start.
The mobile phone has changed people’s life a lot ________ it was invented.
Getting enough sleep is good for _______ health _______ study.
— Hey, boy. You can’t cross the street now. You have to wait _______ the traffic lights turn green. — Oh, sorry and thank you.
Mom was cooking ________ Dad was reading newspapers.