Emissions are gases and other particles（微粒）that are released into the atmosphere as a result of burning fuels and other processes．The most common types generally come from automobiles，power plants，and industrial companies．The results of too many emissions being released into the atmosphere are poor air quality，global warming，and heavy pollution．
    Humans contribute to most air emissions although some animals such as livestock do contribute to a portion of carbon dioxide into the air through digestive process．Despite stricter clean air guidelines，the United States has the highest level of human emissions in the world．This is followed by other industrialized nations like Japan，England，and so on．Many nations are developing rapidly，thus increasing the problem of greenhouse gas emissions in certain areas．The increase in emissions brought about by the introduction of the automobile and fossil fuel power has led to government-mandated（政府強制的）restrictions on companies and car manufacturers．And measures have been taken to help improve air quality and cut down on greenhouse gases．This is a good start，but it is only one step in the right direction．
    The most common emissions released by both human beings and through natural sources are carbon dioxide，methane gas，nitrous oxide，halocarbon，and hexafluoride．Most of them are found in nature but have increased in quantity with the regular burning of fossil fuels．Ozone is another emission that comes as a result of man-made gases combined with natural ones．
    As more is learned about global warming and climate change，environmental groups and some government agencies are trying to find new ways to prevent these things from happening．Technologies which make cars and trucks run without the use of fossil fuels are now available in many areas，and solar energy has become a popular power source in many homes and businesses．If used by many people，these things could truly cut down on the amount of emissions produced by humans each year．
    Clean energy solutions are the best way to stop this problem from getting worse．Clean energy refers to any energy source that does not emit poisonous gases into the air．Most forms of clean energy are also sustainable，meaning that they never run out．The most common sources of clean energy include solar energy and wind energy．Both are becoming widely available for everyday consumers，as well as affordable．

Passage Outline	Supporting details
General introduction	●Emissions are gases and other particles released into the air． ●Lots of emissions（1） contribute/lead contribute/lead to poor air quality，global warming，and heavy pollution．
（2） Sources/Causes/Origins Sources/Causes/Origins of emissions and government's response	●Human beings rather than some animals are（3） responsible responsible for most air emissions． ●Strict（4） restrictions/limitations restrictions/limitations have been placed on companies and car manufacturers．
Analysis of emission components	●Most of the common emissions（5） exist exist in nature and have increased due to human activities． ●Ozone is another emission coming from the（6） combination combination of man-made gases and natural ones．
The best（7） solution/approach solution/approach to emissions and arguments	●Technologies make clean energy（8） available/accessible available/accessible to homes and businesses，which will help（9） decrease/decline/reduce decrease/decline/reduce the amount of emissions． ●Clean energy emits no poisonous gases and will never run out． ●Clean energy is not very（10） expensive/dear/costly expensive/dear/costly and most consumers can have access to it．