1. Everything comes with a price; there is no such ______ thing as ______ free lunch in the world.

A. a, a                      B. the, a                       C. the, /                        D. /, a

2. — I need to advertise for a roommate for next term.

— ______? Mary is interested.

A. Why bother                 B. Why not          C. So what                   D. What for

3. As to the question of whether we will sell our house or who we shall sell the house to, you ______ have an answer by tomorrow.

  A. will                      B. shall                        C. can                          D. must