________ has already been pointed out, only by correcting mistakes can you make progress.

What’s in your bag?— In it two books.

Hello, Betty! Where are you now?— I ________ on the Great Wall of China and talking to you.

If I had followed her advice and worn _______ warm clothing, I wouldn’t have caught such _______ bad cold.

Gone with the wind is a well-known novel. She ____________ it twice.