In an experiment, a scientist decides to study the effect of exercise on cholesterol levels in people. he studies two set of people—those who exercise every day for an hour and those who don’t exercise at all. in this case, the statement that people who exercise for an hour may have lower cholesterol levels is . to test this statement, the scientist would measure cholesterol levels in exercisers and non-exercisers. the cholesterol levels would be . nextreset

Cholesterol is a waxy and fatty molecule, which can have good and adverse effects on health. The amount of cholesterol in the body is variable and is different in each body type.

In the experiment, the hypothesis states that the people who exercised daily have lower amounts of cholesterol.

The scientist performed the experiment on the two sets of population, one in which they performed exercise and the other one not working out at all.

In this experiment, the independent variable is the set in which change in an experiment is to determined concerning the dependent variable.

The result of the test has shown that the population exercising daily has lower amounts of cholesterol compared to the set of people not working out as well.

Therefore, in a scientific experiment, results are carried out based on dependent and independent variables.

To know more about cholesterol, refer to the following link:

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estuaries are the partially enclosed coastal bodies of brackish water formed at the mouth of sea where river meets an ocean. it is a transition zone between river and sea water so estuaries are influenced to both marine environment such as tides, waves and to riverine such as flow of fresh water and sediments. the mixing of sea and fresh water provide high level of nutrients, making estuaries a high product habitats.

many estuaries suffers degradation from a variety of human activities like erosion from deforestation, overgrazing, overfishing, drainage and eutrophication.

so from the above statement answers will be

1. false as estuaries are formed due to both brackish and freshwater.

2.true, due to high productivity estuaries are breeding ground for many marine species.

3. direct and indirect activities of man that contribute to pollution and deposition of sediments.

d. planting trees

the trees take in carbon to make oxygen.