Air Pollution, Free PDF Download - Learn Bright - Free Printable

Here is the step-by-step solution to fill in the blanks using the words from the list.

Step 1: Analyze the first paragraph
* "When the air becomes dirty it is not as easy to clean." (From the list, 'dirty' fits best here).
* "When there is dirt and other substances in the air that should not be there, it is called air pollution." (This is the definition of air pollution).

Step 2: Analyze the second paragraph
* "Air pollution is made up of gases, dust, odors, particles, smoke, fumes, and other substances." ('Particles' like dust are common pollutants, and 'substances' is a general term for the other things listed).

Step 3: Analyze the third paragraph
* "Air pollution affects the Earth’s atmosphere." (The atmosphere is the layer of air around Earth).
* "The atmosphere of the Earth is like a blanket of air which protects all life." (The atmosphere supports living things).

Step 4: Analyze the fourth paragraph
* "The atmosphere protects living organisms from the heat of the Sun during the day..." (It blocks intense solar heat/radiation).
* "...and at night it prevents the warm air from escaping." (At night, the atmosphere acts like insulation to keep Earth warm).

Step 5: Analyze the fifth paragraph
* "The pollution in the air, though, affects this “blanket” and becomes harmful to life on Earth." (Referring to our planet).

Step 6: Analyze the sixth paragraph
* "The substances causing the air to become dirty are called pollutants." (This is the specific name for pollution-causing agents).
* "Some examples include gases with harmful chemicals in them." (Pollutants often contain dangerous chemicals).

Step 7: Analyze the seventh paragraph
* "It is difficult to avoid the pollution in the air since it is the place where people get the oxygen to breathe and live." (Humans need oxygen from the air).

Step 8: Analyze the eighth paragraph
* "Pollution can travel with the wind from one place to another..." (Wind carries air pollutants).
* "...and spread over a large number of miles." (Wind can carry pollution long distances).

Step 9: Analyze the ninth paragraph
* "Pollution can be caused by humans or it can also occur naturally." (Pollution sources are either man-made or natural).

Step 10: Analyze the final sentence
* "For example, natural pollution may come from volcanoes." (Volcanoes release ash and gas, which is a natural source of pollution).

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Final Answer:

1. dirty
2. pollution
3. particles
4. substances
5. atmosphere
6. life
7. heat
8. night
9. Earth
10. pollutants
11. chemicals
12. oxygen
13. wind
14. miles
15. humans
16. naturally
17. volcanoes