Obligation and Prohibition

Front

Please remember, you _________ leave trash or food in the cafetaria.

Back

shouldn´t

Front

To save ocean resources, we __________ stop ocean pollution.

Back

must

Front

We _______ take care of the earth and stop polluting it.

Back

must

Front

You _______ leave trash in the mountains when you go hiking.

Back

musn´t

Front

To save the trees, we ________ protect the forests.

Back

have to

Front

To keep parks clean, we ________ pick up our food after a picnic.

Back

have to

Front

We ________ throw bottles and cans into our oceans and rivers.

Back

can't

Front

Students ________ use plastic or disposable plates at school lunch.

Back

shouldn´t

Front

Planting trees is a good way of recovering from deforestation and everybody _________ help.

Back

can

Front

We _________ protect the oceans, or our resources will disappear.

Back

have to