–I feel tired and sleepy. –Why not stop __________?

In the old days, people lived in caves and they had to make a fire _________themselves warm. 

Let’s ________ football this Sunday.

—I’m sorry I forgot      the letter for you! I’m really busy these days”—It doesn’t matter, I’ll post it myself.”

One way _____ this problem ______ search for some information on the Internet.