Match the parts of the sentences. Consult text B.

1) Platinum and palladium act	a) engine performance
2) These substances improve	b) as catalysts in a chemical reaction
3) Most cars	c) catalytic converters
4) Leaded fuel contaminates	d) now use lead-free gasoline
5) Several different systems are used	e) before the car leaves the factory
6) Few cars now depend	f) to lubricate the engine parts of a car
7) The lubricant is sealed in	g) on the splash system alone

21. Grammar Revision. Passive Reporting Verbs or Infinitive Constructions. These sentences are all in rather formal English. How would you say the same things in conversational English?

Model:

a) The two most common internal-combustion engines are known to be the gasoline and the diesel engines.

b) The two most common internal-combustion engines are the gasoline and the diesel engines.

1. Modern transportation is known to rely on internal combustion engines.

2. Most cylinder blocks and heads are known to be of cast iron.

3. Some cylinder blocks are said to be of aluminium.

4. Alternative fuels are said to appear in our country.

5. Diesel fuel is considered to offer better fuel economy.

6. RON requirements are believed to vary according to engine type.

7. Afterburners are believed to reduce pollution.

22. Try it. How Words Work…

A. Pronounce the derived words correctly.

1. “I-n-c-h”: intake – nut – compression – cycle

2. “R-a-t-i-o”: range – adjustable – test – intake – optimize

3. “T-o-p”: tank – oil – petrol

23. Study the diagram of a cooling system and explain to your group-mate: how the plumbing is connected.

Although gasoline engines have improved a lot, they are still not very efficient at turning chemical energy into mechanical power. Most of the energy in the gasoline (perhaps 70%) is converted into heat, and it is the job of the cooling system to take care of that heat. In fact, the cooling system on a car driving down the freeway dissipates enough heat to heat two average-sized houses. The primary job of the cooling system is to keep the engine from overheating by transferring this heat to the air, but the cooling system also has several other important jobs.

The engine in your car runs best at a fairly high temperature. When the engine is cold, components wear out faster, and the engine is less efficient and emits more pollution. So another important job of the cooling system is to allow the engine to heat up as quickly as possible, and then to keep the engine at a constant temperature.

Date: 2015-12-18; view: 788

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