History is _______ a subject which only lets us know something in history..

After two years’ research, we now have a __________ better understanding of the disease. 

I don’t mind picking up your things from the store. ______, the walk will do me good.

I thought she was famous, but none of my friends have ______heard of her.      

---Laura calls on her teacher pretty ____, doesn’t she? ---Yes. At least three times every week.