题干
—Must I do my homework now?
—No, you . You may have a rest.
A：mustn't
B：needn't
C：can't
D：wouldn't
答案(点此获取答案解析）
B
—Must I do my homework now?
—No, you . You may have a rest.
A：mustn't
B：needn't
C：can't
D：wouldn't
。恒容时，温度升高，H2浓度减小。下列说法正确的是
