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
《曹刿论战》
十年春,齐师伐我。____
公与之乘,战于长勺。公将鼓之。刿曰:“未可。”齐人三鼓。刿曰:“可矣。”齐师败绩。公将驰之。刿曰:“未可。”下视其辙,登轼而望之,曰:“可矣。”遂逐齐师。