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and clean it. 3. I’ve heard that one tree has the power of 15 air conditioners. Is that right? No. One trees has the power of five air conditioners. 4. Scientists know a lot about trees, don’t they? No. they are only now beginning to understand them. 5. Can trees really municate with one another? Yes. For example, if insects attack a tree, it can warm its neighbors. 6. And can they really protect themselves from insects? Yes. They can produce a chemical that makes their leaves taste nasty. Answer the questions 7. Can trees help one another? Yes. For example. They can join their roots together under ground and pass food and water around. 8. Is it true that, every year, there are fewer and fewer trees in the world? Yes. The reason is that people cut down millions of trees, but replace hardly any of them. Listening Listen and plete the notice below by putting one word in each space. Eight reasons for helping to plant trees: 1 Trees make streets more ________. 2 Trees make stree