These are some ways how scientists and engineers develop, use and refine models.
1. Imagine. They have to know what exactly trying to model. They have to imagine and brainstorm what are the things to be considered.
2. Reason. Next, they need to answer the questions brought from their brainstorming. They need to be able to reason out.
3. Calculate and Predict. Once they know it, that's the time they can start modelling and calculate - and predict.
Deforestation. The animals forest that they once lived in are bein cut down.
Hello!
The answer you were looking for is....
(D) Nonpoint source pollution is difficult to regulate, because its source is difficult to track.
What’s is the cart to this problem?
<u><em>Naturally acquired active immunity:</em></u> It happens when someone is exposed to a live disease and gets the disease. The person then becomes immune as a result of the first immune response.
It's sort of like a fall and learn to get up for the body.
<em><u>Artificially acquired active immunity</u></em>: It can be isert into the body by a vaccine so you won't get sick. That's why if you get a flu shot, you won't get the flu, if you get a chicken pox vaccine, you won't get the chicken pox.
It's like you're body has a personal guide telling it where and where not to step in order to not fall.
