Answer:
An understanding of biology can help you make choices and decisions that affect your health. Biologists and other scientists research environmental issues such as pollution, biodiversity,land conservation, and natural resource use.
Explanation:
Hope this helped Mark BRAINLIEST!!!
There are often not more than one or two independent variables tested in an experiment, otherwise it is difficult to determine the influence of each upon the final results. There may be several dependent variables, because manipulating the independent variable can influence many different things.
I think it is 60 i believe so