—Where did you get this book?—I picked it up from a second­hand bookshop if you ________ know.
#62316
A
must
B
will
C
can
D
shall
推荐题目
 I ____ have been there, but I ____ not find the time.
#62724
A
could; must
B
must; could
C
should; could
D
should; would
— _______ we clean the classroom at once?  — No, you _______. You _______ clean it after school. 
#78132
A
Must; needn’t; may
B
Must; mustn’t; can.
C
Shall; can’t; must
D
Need; mustn’t; may