—Whereonearthdidyougetthebook?—It’sfromMary,ifyou

問題詳情：

 —Where on earth did you get the book?

—It’s from Mary, if you ________ know.

A. should                   B. could                    C. must                    D. may

【回答】

C

知識點：虛擬語氣與情態動詞

題型：選擇題