must/mustn"t, should/shouldn"t

Children........spend a lot of time at the computer.

We .......keep our planet clean!

You ......clean your teeth every day.

You ......eat too many sweets and drink too much coffee.

You .........skip breakfast, because it`s very important for your health.

Teenagers.............smoke or drink alcohol.

You ... drink a cup of milk every day

You ..........do your homework in time.

Teenagers...........be rude to their parents.

You .......make noise at the library.

You ........study harder to get better marks.

You .......use your phones at the lessons.

Tom has had earache for two weeks! He ....... see a doctor.

Brian looks tired. He ...... works so hard.

People ...... cut down trees. They ...... plant more trees.

You ........lie to your parents or your friends.

Speak nicely to the shop assistant. You ..... be rude!

Peter has got a terrible headache. He.... listen to loud music. He ....... go to bed early.

Karen sprained her ankle yesterday and the doctor said that she ..... walk

People________ eat a lot of fruit to be healthy.