根据汉语意思完成句子。
1. 刀子用来切东西。
    Knives _______ _______ _______ cutting things.
2. 孩子们，随便吃点儿水果吧。
    _______ _______ to some fruit, children.
3. 吉姆周末经常帮妈妈洗餐具。
    Jim often helps his mother _______ _______ _______ on weekends.
4. 吃太多的快餐食品对你的健康有害。
    Eating _______ _______ fast food is bad for your health.
5. 一吃完就离开是相当无礼的。
    It's quite rude if you leave _______ _______ _______ you finish eating.