---I haven’t got the reference book yet, but I’ll have a test on the subject next month.
---Don’t worry. You have it by Tuesday.
A. could
B. shall
C. must
D. may
网友回答
A. could
(答案→)B. shall
C. must
D. may
解析：句意：上文，我还没有拿到参考书，但是下个月我有个这个科目的考试。下文，别着急。周二你就可以拿到了。could能够must必须may可能，这里表示对说话人的承诺故用shall，选B。