Mấy anh chị làm giúp em với ạ , không cần giải thích cũng được ạ, em xin cảm ơn

3. Fuel can be cut down by having fewer cars on the roads. (consume) 4. We must learn about keeping the environment (pollute) 5. He is one of the most famous in the world.(envitonment) that our environment is more and more polluted. 6. It is (disappoint) 7. He examination.(disappoint) ...