What gas is increasing in large amounts due to human activities?

This is so important ugh its 25 points

An uncomfortable feeling in the ears when descending in an airplane is caused by changes in air pressure on the: a. inner ear b. middle ear c. eardrum d. hammer/anvil

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.