It is the prevention of disease ______its successful treatment that has led to the rapid increase of the world’s population.

— You keep on coughing. What's the matter?
— Oh， I've got a cold. Nothing serious， ____.

We’ve published large quantities of books. This year______ we’ve published three million copies.

Mr. Brook didn’t come back at the usual time last night. ______, he met some friends and stayed out until midnight.

I just keep working hard as I have done, and ________ it will pay off. It has done so far and so I just have to do the same.

As soon as his teacher begins lecturing, he begins to doze off, not intentionally but _____.

Father       goes to the gym with us although he dislikes going there.

— How do you find his new novel?    
— His previous ones are great, and I think this one is _____ worth reading.

The first time he had a dinner with some high officials, he felt _____ uneasy.

You are driving too fast. Can you drive_________?