warm
Exercise 17
Problem：Deciding where to put an industrial park.
Solution：Using these empty mines for it.
Main Idea：It is about how the underground industrial park was established in Kansas City.
Problem：How to help the economy but not damage the forest.
Solution：The Brazilians have made a deal with Pepsi-cola Company to introduce the beverage in north America.
Main Idea：By selling a natural product， Brazilians will build a strong economy without endangering the rain forest.
Problem：The usual method for cleaning up ground pollution is very expensive and complicated.
Solution：Scientists use trees and plants that can eliminate certain polluting substances.
Main Idea：Scientists now find that there is a better and less expensive way to clean up the ground pollution by using trees and plants they identified.
Exercise 18
Exercise 19
S cc l ce ps s ce cc s ce
Exercise 20
1
Sentence: d Pattern: ce
2
Sentence: e Pattern: s