You must wear a seatbelt in the car to ensure your safety.（你必须在车里系安全带以确保你的安全。）

We must finish this project before the deadline.（我们必须在截止日期前完成这个项目。）

Students must listen carefully in class to learn well.（学生们必须在课堂上认真听讲才能学好。）

She must be at home because her car is in the driveway.（她一定在家，因为她的车在车道上。）

He must study hard if he wants to pass the exam.（如果他想通过考试，他必须努力学习。）

They must follow the rules when they play the game.（他们玩游戏的时候必须遵守规则。）

I must go to the supermarket to buy some groceries.（我必须去超市买些杂货。）

The children must be back home before it gets dark.（孩子们必须在天黑前回家。）

You must take your medicine three times a day as prescribed.（你必须按照医嘱一天吃三次药。）

We must protect the environment for our future generations.（我们必须为我们的后代保护环境。）

Workers must wear helmets on the construction site.（工人在建筑工地上必须戴安全帽。）

It's getting late. I must leave now.（天色渐晚。

我现在必须离开了。）

She must be very tired after a long day at work.（工作了一整天后，她一定很累了。）

He must practice speaking English every day to improve his skills.（他必须每天练习说英语来提高他的技能。）

They must arrive at the airport two hours before the flight.（他们必须在航班起飞前两小时到达机场。）

You must be quiet in the library so as not to disturb others.（你在图书馆里必须保持安静以免打扰他人。）

We must save water as it is a precious resource.（我们必须节约用水，因为它是一种宝贵的资源。）

The dog must be hungry. Look at how it's wagging its tail.（这只狗一定饿了。

看它摇尾巴的样子。）

I must clean my room before my parents come back.（我必须在父母回来之前打扫我的房间。）

You must respect your elders and be polite to them.（你必须尊重长辈并对他们有礼貌。）