(al tə tüd): The vertical distance of an object above a given level (such as sea level).

(ak səs): A straight line about which a body or geometric figure rotates.

(be nә fit): A good or helpful result.

(klī mǝt): The average weather conditions of a particular place or region over a period of years.

(kō ni f(ǝ) rǝs): Characterized by leaves resembling needles or scales in shape and including forms (like pines) with true cones.

(kǝn trōl): A variable factor that has been kept constant and which is used as a standard of comparison to the experimental component in a controlled experiment.

(di si jǝ wǝs): Having parts, like leaves, that fall off or shed seasonally or at a certain stage of development in the life cycle.

(ē kə lä ji kəl): Of or relating to the environments of living things or to the relationships between living things and their environments.

(es chə wer ē): A water passage where the tide meets a river current.

(fä sǝl fyü(ǝ)l): A fuel (such as coal, oil, or natural gas) formed in the Earth from plant or animal remains.

(hī pä thǝ sǝs): An assumption or idea that is proposed for the sake of argument so that it can be tested to see if it might be true.

(nī trə jən): A colorless tasteless odorless element that occurs as a gas which makes up 78 percent of the atmosphere and that forms a part of all living tissues.

(äb sәr vā shәn): An act of recognizing and noting a fact or occurrence often involving measurement with instruments.