May we leave the classroom now? No, you _____. You_____ to leave until the bell rings.
A:mustn't, are allowed
B:don't have to , are supposed
C:needn't , aren't allowed
D:can't , aren't supposed
读城市化进程和某国人口自然增长率变化曲线图。据此完成下列各题。
某学校组织郊游后,在学校广播中特殊表扬七年一班许莉莉同学:“许莉莉同学在郊游途中,没丢一个垃圾,甚至把同学扔的垃圾捡起一并带走,值得所有同学学习。”此表扬被同学发上互联网,引得同学们热议。