His English, ______ used to be very poor is now excellent.

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

Can you keep a secret?—You ________ worry—I’m not going to mention it to anyone.

Heilongjiang is in the _____of China.

there is no such thingas a free lunch in the world, one millionpeople of the city decided to build their home by themselves.