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.
Answer would be D)<span>all of these</span>
When climbing a hill or mountain, there are different condions which the body reacts to, first: the body begins to exercise, since it must carry all our weight when climbing up a hill, this generates that the heart accelerates and pumps the blood more quickly so that it reaches our whole body out, and the second one, is that at a higher height, less oxygen, if already, our body comes with the heart shaken by the physical exercise, now it has to accelerate your breathing to get the necessary oxygen for the blood and the body, these two things make us breathe heavily.
Answer:
Na2He
Explanation:
This is the correct answer
