The answer is B It must be testable.
Semen is the correct answer
It might be 23% because 77% of water covers earth and most of the water is either polluted or salt water.
An experiment or survey must be controlled in order to receive accurate results.
In an experimental group, the independent variable is changed. But in the control group, the independent variable stays the same.
Valence electrons are the electron on the outer energy level and they are important because they tell if that element is compatable
