The law of universal gravitation states that any two objects in the universe that have mass. without exception,
a. attract each other
b. repel each other
c. combine to provide a balanced force
d. create friction

Which of the following is true about the introduction of a non-native species to an environment? (a) they usually adapt quickly so they can have a positive affect on the environment. (b) they can disrupt the environment and cause much damage and devastation to native species. (c) they usually become predators in a food chain and to keep prey populations under control. (d) because the native species are better-adapted to the environment, the non-native species always end up dying out.