Our geography teacher told us that the earth ______ the sun.( )
went around
goes around
is going around
was going around
They have been friends __________ they were at primary school.
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.