Maybe c or d
Step by step:
Fusion and gravity
Fusion and gravity keep the sun from blowing itself up. A large amount of energy is released by the
sun. Protons are fused together to form helium atoms due to the high heat and
pressure at the center of the sun. The Sun does not blow itself up from the
outer pressure of nuclear fusion in as much as the inner force of gravity
balances it.
Manipulated Variable:The speed working on maths problems
Responding Variable: The group that use¬ using a calculator
Controlled Variable:The same maths quetions
The function of a plant's cambium layer is to <span>produce new cells.</span>
