I need help with #4 I will give brainliest

Back in the frontier days there was very little concern about water shortages. People did not have too worry about not having enough water. Today people do have to keep in mind how much water they are using. some people do worry about not having enough water.

Explanation:

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measuring light intensity

light meters can be used to measure light intensity. the meter is held at the soil surface and pointed in the direction of the maximum light intensity, and then the meter is read.

errors can be made when measuring light intensity by accidentally shading the light meter. the reliability of the results can be checked by taking many samples.

c. establishing proper sleep hygiene