Answer:
experimental method.
Explanation:
Based on the information provided within the question it can be said that the method that is being described is called the experimental method. This method, like described in the question, refers to manipulating one variable in order to see the effects that it causes in another variable, and is done in order to test the hypothesis and decide whether it s refuted or not.
Shiny hair is not related to smoking, nor is it a result of smoking.
The two years are between 12 and 15
Answer:
pay more attention in class
