Answer:
D
Explanation:
For It to be controlled more than one variable has to stay the same
Scientists change the independent variable; The dependent variable is the one that reacts to the independent variable.
Since the half life of the radioactive isotope is 4,000 years, after 4,000 years the amount of the isotope would decrease by half. (Hence the name, half life.) So, after 4,000 years, there would be half of the isotope left in the fossil.
Answer:
Not really sure, buts its either B or C.
