don't have to do/mustn't do

don't have to 与 mustn't 的含义完全不同。前者意为“不必”（not obliged to）、“不需要”（not necessary），后者意为“不许”“不应当”“一定不要”“绝不要”。请分析下面的实例及其译文：

1. We don't have to go to school on Sundays. (Wood) 星期天我们不必上学。

2. They didn't have to worry about money. 他们不必为金钱操心。

3. If you want to be a nurse, you must be kind and patient, and you mustn't be lazy, but you don't have to be good at sport. (Leech) 如果想当护士，你必须和气耐心，不能懒惰，但不必擅长体育。

4. You mustn't drink water from the river. 你们绝不要喝这河里的水。

5. You mustn't tell the teacher about it. 不许把这件事告诉教师。

6. I must speak to Helen soon. She mustn't learn this from someone else. (Greene) 我必须立即跟海伦谈话。她绝不要从另外的人那里听到这个。

7. You mustn't keep us waiting. (CGEL) 你绝不要让我们等。

8. You mustn't go swimming today. (CGEL) 今天不许你去游泳。

关于表示推测的 mustn't, 见 mustn't/can't。