1. I'm not sure
2. false
3. true
The answer would be true due to the fact that observing is really just looking at the situation, defining it and receiving data, whereas it can be used to add info supporting the problem you wish to explain. Though it can be false while observation can just be looking over an item or object to find data to help you answer your already defined problem.
If you expose yourself to much to toxicity or overall what you eat/ air bruv..
In the case of fish if you polute plastic into the ocean the water will break up the plastic and the fish will confuse the little particles of plastic as food and will try to eat it and can die