Explain why it is important to keep all variables that might affect the dependent variable, other than the manipulated variable constant?

The transfer of heat through the movement of a gas or liquid a. convection b. conduction c. radiation

Which accurately compares concave and convex lenses?

The star betelgeuse is about 600 light-years away. if it explodes tonight, a. we'll know because debris from the explosion will rain down on us from space. b. we'll know it immediately because it will be brighter than the full moon in the sky. c. we won't know about it until 600 years from now. d. none of the above.