I ____ a poem last night. [ ]
A. wrote
B. writes
C. writing
答案:A
--- I don’t mind telling you what I know.
--- You _______. I’m not asking you for it.
A.may not
B.can’t
C.don’t have to
D.mustn’t
当循环队列非空且队尾指针等于队头指针时,说明循环队列已满,不能进行入队运算。这种情况称为______。