Answer :
Answer:
Natural source
Mobile source
Explanation:
Dear students, as we've been studying air pollution, we've learned that it comes from various sources. Now, let's think about which sources would be difficult for a small community to control.
Let's consider natural sources. Imagine a volcanic eruption or a large forest fire. Can a small town stop these kinds of events? Of course not. That's why natural sources are one of the pollution sources that communities can't control.
Now, let's look at mobile sources. What are these? They're transportation vehicles like cars, buses, and airplanes. Imagine there's a major highway passing near your town. Is it easy to reduce traffic on this road? Not really. Because these roads don't just belong to that town, they serve a wider region.
Therefore, natural sources and mobile sources are the pollution sources that small communities would find most difficult to control on their own. Communities might have a bit more influence over other sources - like local factories or home heating, for example.
