Unit 3. What’s Your Knowledge? » Стр.87 (19)

Put the dialogue into its logical order. Use a dictionary if necessary. A: 5. Student: What about the food chain? What's that? B: 6. Teacher: Well, let's imagine a fox, a snake and an owl.They all eat rabbits, mice and voles, who in turn eat nuts, leaves, and seeds. If you kill all the snakes, there will be too many mice and voles and there will be an unbalance. C: 1. Student: Can you give me an example of an ecosystem? D: 4. Teacher: Well, all the animals and plants in a community are connected by the food chain. E: 7. Student: Right. Do you know any examples of this happening? F: 2. Teacher: Yes, a tree in a forest can be. The tree offers a home to many birds and insects and plants like ferns, moss and wild flowers put down roots in the bark of the tree or grow up the trunk. G: 3. Student: Oh, in what way is that? H: 8. Teacher: Yes, I do. In the US in the Grand Canyon National Park the wardens shot all the wolves, coyotes and wild bobcats to protect the deer. Then there were too many deer and soon there wasn't enough grass for them, so they ate the young trees and shrubs.Then the deer actually began to die of starvation, there were so many of them.