问题补充：
---Excuse me. I’m looking for Be the Best of Yourself.
---Sorry. The book you ask forout.
A. is selling
B. is sold
C. was selling
D. will be sold
答案：
A. is selling
(答案→)B. is sold
C. was selling
D. will be sold
解析：句意：对不起，你找的书卖光了。动作的承受者作主语，用被动语态。其结构是，主语+be+done.故选B
