21. — Can I look at other dresses before I decide which one I’d like to buy?

    — Of course. ___________.

   A. Have a good time                       B. Enjoy yourself  

 C. Take your time                                      D. It doesn’t matter

22. I bought a vase of the Ming dynasty at such a low price at the Sunday market. It was really a nice __________.

A. bargain              B. value               C. sale                  D. prize

23. — Where is the panda?

— It __________ by the doctor now.

A. was being examined                     B. is being examined    

C. will be examined                                  D. has been examined