Modal Auxiliaries

To reduce paper waste, we ________ recycle more. (advice)

• can't

• must

• should

To reduce food waste, we _______ compost (put in the soil). (ability)

• have to

• can

• must

To reduce metal waste, we _______ drink less soda in cans or recycle more. (advice)

• should

• can

• have to

To help protect our oceans and sea life, we ______ solve our plastic waste problem. (obligation)

• must

• should

• may

To save and protect our limited petroleum resources, we ______ reduce, reuse and recycle our plastic waste. (obligation)

• can

• might

• have to

Americans ______ eliminate much of their food waste by planning meals and by eating leftovers. (ability)

• must

• can

• may

Composting _____ help solve our food waste problem. (ability)

• should

• must

• could

We _____ find places nearby us to recycle our old and broken cell phones. (advice)

• ought to

• should

• might