The source of information was biased. It was like walking along a river bank in the country and asking everybody you meet whether they like fishing. Or asking 500 people sitting in the bleachers whether they like baseball.
I'm sure the scientist would have gotten different data if she interviewed 500 teenagers at neighborhood basketball courts, or 500 teenagers at a rock concert.
A circuit is a closed circle that electricity can flow through.
Vapor is usually made with water and it would be made with gas.
If there is no friction, the force that moves the box forward horizontally must be matched by the same force.
If there is friction, then the force moving it forward = frictional force + the additional force you need to add.
B. False
Endothermic reactions absorb heat.