1. We keep ________ burning trash to reduce the amount of garbage to protect our environment. 2. I look ________ to hearing ________ you and seeing good response ________ your company. 3. It’s a good idea. Let’s do something ________ environment pollution. 4. The teacher divides our class ________ 4 group to discuss reasons _________ environment protection. 5. They are collecting all the plastic bags and taking them ________ the garbage dump now. 6. I’d like you to provide us ________ non-toxic products. 7. What will happen if the pollution goes __________? 8. Local residents are pleased that we don’t throw garbage _______ the lakes. 9. It’s difficult to prevent lazy students ________ throwing trash. 10. I think people should use public transport instead ________ using their own motorbikes and cars. 11. We should discuss ________ our partners the best ways to protect our environment. 12. Nam persuaded his mother ________ buying a laptop for him. 13. The school yard is littered ________ waste paper. 14. The streets are covered ________ the fog. 15. Our parents are happy that we can save us ________ doing bad things.