Stuart designed and built a water filter in class. he wants to know if it will make water from lakes or streams safe to drink. which of the following would it be best for stuart to measure in an experiment in order to test his design and answer this question?

The correct answer is "The amount of bacteria and impurities in water both before and after it passes through his filter"

Explanation:

Although each of these properties of Stuart's filter may be worth testing, the one that will tell him whether his filter can make lake water safe to drink is the amount of bacteria, parasites, and impurities in water both before and after it passes through his filter. Some filters are good at removing impurities, but not bacteria. Other ways of purifying water may kill bacteria but not remove impurities.

so you know what happened be fore you were alive

explanation: