2 Rewrite the sentences 1-8 by replacing the underlined phrases with words from Exercise 1. You can make other changes as well if necessary. Example: In springtime the ice in the Arctic Circle returns to a liquid state. In springtime the ice in the Arctic Circle melts. 1 An effective way of producing power is to use energy from the sun. 2 At the North and South Poles, water becomes so cold that it changes from a liquid to a solid state. UNLIVEWORKS Unit 7 3 If you raise the temperature of water to 100 degrees Centigrade, it boils. 4 This power station uses energy produced by atomic fission to generate electricity. 5 Oil is physical matter found under the surface of the earth. 6 In order to make a fire, some kind of combustible material such as wood is needed. 7 If you lubricate an engine, it will function more effectively. 8 Refrigeration is the main method of lowering the temperature of food.

1. "An effective way of producing power is to use energy from the sun" được viết lại thành "Solar power is an effective way of producing power" bằng cách sử dụng từ "Solar power" thay cho "energy from the sun".<br />2. "At the North and South Poles, water becomes so cold that it changes from a liquid to a solid state" được viết lại thành "At the North and South Poles, water freezes" bằng cách sử dụng từ "freezes" thay cho "changes from a liquid to a solid state".<br />3. "If you raise the temperature of water to 100 degrees Centigrade, it boils" được viết lại thành "If you heat water to 100 degrees Centigrade, it boils" bằng cách sử dụng từ "heat" thay cho "raise the temperature".<br />4. "This power station uses energy produced by atomic fission to generate electricity" được viết lại thành "This power station uses nuclear energy to generate electricity" bằng cách sử dụng từ "nuclear energy" thay cho "energy produced by atomic fission".<br />5. "Oil is physical matter found under the surface of the earth" được viết lại thành "Oil is a fossil fuel found under the surface of the earth" bằng cách sử dụng từ "fossil fuel" thay cho "physical matter".<br />6. "In order to make a fire, some kind of combustible material such as wood is needed" được viết lại thành "In order to make a fire, you need a fuel such as wood" bằng cách sử dụng từ "fuel" thay cho "combustible material".<br />7. "If you lubricate an engine, it will function more effectively" được viết lại thành "If you oil an engine, it will function more effectively" bằng cách sử dụng từ "oil" thay cho "lubricate".<br />8. "Refrigeration is the main method of lowering the temperature of food" được viết lại thành "Refrigeration is the main method of cooling food" bằng cách sử dụng từ "cooling" thay cho "lowering the temperature".