Two laws passed to prevent or decrease water pollution were the clean water act and the clean water act and the

Safe Drinking Water Act

Explanation:

These are the two laws that were passed to prevent or decrease water pollution. The Safe Drinking Water Act is the main federal law in the United States that ensures safe drinking water for the public. This law applies to every public water system in the United States (over 151,000). This act, however, does not cover private wells or bottled water.

satellites are frequently used to make observations of the orbit on earth

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.