Which of the following correctly shows the four most abundant gases in the earth's atmosphere in order from most abundant to least abundant?
a. nitrogen, oxygen, argon, carbon dioxide
b. nitrogen, oxygen, carbon dioxide, argon
c. carbon dioxide, oxygen, nitrogen, argon
d. oxygen, nitrogen, argon, carbon dioxide

Based on the observation that only male crickets produce a song, you hypothesize that a male's song is a form of communication to potential mates. you set up a simple experiment to test this hypothesis. in the laboratory, you place a male snowy tree cricket in enclosure a, which is adjacent to enclosureb. in enclosure b, you place other insects, one at a time, and observe their responses to the male's song. the enclosures are designed so that the two insects being tested cannot see or smell each other, but sound is transmitted from enclosure a to enclosureb.

The diagram shows the development of the oocyte and the follicle during the menstrual cycle. identify at which stage in the cycle the hormone levels are at their highest and most active.

Veronica and her little sister, monique, are playing on a seesaw. if veronica weighs 75 pounds, and monique weighs 60 pounds, which statement is true?