—Where did you get this book?—I picked it up from a second­hand bookshop if you know.

问题补充：

—Where did you get this book?

—I picked it up from a second­hand bookshop if you know.

A. must

B. will

C. can

D. shall

答案：

(答案→)A. must

B. will

C. can

D. shall

解析：答案：A考查情态动词辨析。句意为：你在哪买到这本书的？如果你非要知道的话，我是在二手书店买到的。must此处表示“非要，偏偏”，符合题意，故选A。