1.1.1　Air Pollution

Text（课文）

At present，all vehicles rely on the combustion of hydrocarbon（HC）fuels to derive the energy necessary for their propulsion.Combustion is a reaction between the fuel and the air that releases heat and combustion products.The heat is converted to mechanical power by an engine and the combustion products are released to the atmosphere.An HC is a chemical compound with molecules made up of carbon and hydrogen atoms.Ideally，the combustion of an HC yields only carbon dioxide and water，which do not harm the environment.

Actually，the combustion of HC fuel in combustion engines is never ideal.There are other emissions from conventional fossil fuel-powered vehicles，including carbon monoxide（CO）and nitrogen oxides（NO and NO2，or NOx）from burning gasoline；hydrocarbons or volatile organic compounds（VOCs）from evaporated，unburned fuel；and sulfur oxide and particulate matter（soot）from burning diesel fuel.These emissions cause air pollution and ultimately affect human and animal health.

New words and expressions（单词和短语）

1.New words（单词）

2. Expressions（短语）

Notes to the text（难点解析）

★1.At present，all vehicles rely on the combustion of hydrocarbon（HC）fuels to derive the energy necessary for their propulsion.目前，所有车辆依靠碳氢化合物类燃料的燃烧，以获得其驱动力所必需的能量。

★2.The heat is converted to mechanical power by an engine and the combustion products are released to the atmosphere.热量经发动机转换为机械功率，而燃烧生成物则排入大气。

★3.There are other emissions from conventional fossil fuel-powered vehicles，including carbon monoxide（CO）and nitrogen oxides（NO and NO2，or NOx）from burning gasoline；hydrocarbons or volatile organic compounds（VOCs）from evaporated，unburned fuel；and sulfur oxide and particulate matter（soot）from burning diesel fuel.以传统化石燃料为能量源的车辆还会产生其他的排放物，包括汽油燃烧产生的一氧化碳（CO）和氮氧化物（NO、NO2和NOx）、来自蒸发和未完全燃烧气体中的碳氢化合物和挥发性有机化合物（VOCs）、柴油燃烧产生的硫氧化物和颗粒物（炭烟）等。

Exercises（练习）

◆1.Translate the following passages（expressions）into Chinese（英译汉）

（1）combustion engine

（2）harm the environment

（3）Combustion is a reaction between the fuel and the air that releases heat and combustion products.

◆2.Translate the following passages（expressions）into English（汉译英）

（1）机械功率

（2）二氧化碳

（3）热量经发动机转换为机械功率，而燃烧生成物则排入大气。

（4）事实上，在热力发动机内碳氢化合物类燃料的燃烧绝非理想化的。

◆3.Fill in the blanks with the suitable words according to the text

An HC is a______compound with molecules made up of______and hydrogen atoms.Ideally，the combustion of an HC yields only______and______，which do not harm the______.

◆4.Directions:Answer the following questions briefly according to the text

（1）What is combustion？

（2）What will cause air pollution and ultimately affect human and animal health？

Reading material（阅读材料）

Indeed，green plants“digest”carbon dioxide by photosynthesis.Carbon dioxide is a necessary ingredient in vegetal life.Animals do not suffer from breathing carbon dioxide unless its concentration in air is such that oxygen is almost absent.