Earth's atmosphere is composed of about 78 percent of what gas? a. carbon dioxide c. water vapor b. oxygen d. nitrogen select the best answer from the choices provided

Which units ate used to measure both velocity and speed? check all that apply

Which of the following is an effect of the uneven heating of the earth by the sun? a sea breeze a land breeze a convection current all of the above

8) animals respond in various ways to stimuli detected through their senses. some of these responses are stimulated by the presence of danger. which of these animal responses is the best example of a response to an immediate threat? a) a rooster crows every morning at the first sign of light. b) as something approaches an octopus, it shoots a cloud of ink. c) from late fall until spring, bears hibernate to preserve energy. d) a dog is getting hot in the sunlight, so he moves to a shaded area.