The thought of going back home was _______ kept him happy while he was working abroad.

Do you need ___ coffee?  

---- Where is my blue shirt? ---- It’s in the washing machine. You have to wear ____different one. 

---Which book do you think is the most useful to my studies?---________, as long as you read it. In fact, they are out of date.

—Why don't we take a little break?—Didn't we just have________?