Which of the following statements is true?

1. The total amount of water in an ecosystem is always increasing.
2.Thermal pollution is the main disadvantage of hydroelectric power.
3.Wood and water are nonrenewable natural resources.
4. The greenhouse effect is primarily caused by cars and trucks.

Organisms within a population must compete for resources to survive

Acar company is testing seatbelts using crash test dummies. the company finds that when cars come to a sudden stop, the crash test dummies' bodies continue to move forward. the seat belt keeps the crash test dummies from hitting the back of the seat in front of them. why do the crash test dummies' bodies continue to move forward even though the car stopped? a. the friction opposing their bodies' movement keeps them in motion. b. the inertia of their bodies keeps them in motion. c. the forward acceleration of the car keeps them in motion. d. the gravity pulling on the car keeps them in motion.

As a small change in a person's dna can cause a genetic disorder