How was aristarchus's explanation of the movement of objects in the sky different from other scientists' earlier explanations? check all that apply.

a. he discovered venus’s phases.
b. he argued that earth rotates on its axis.
c. he explained the concept of retrograde motion.
d. he described the epicycles of the planets in the sky.
e. he stated that the sun is the center of the solar system.

Imagine you work as a consultant, and your daily job involves listening to the constructive criticism of others. as part of your job, you must listen to opposing viewpoints to make important decisions. in this activity, you are a consulting dam engineer. you must make a decision about four different dams; should they be repaired, taken down, or left alone? you will listen to contrasting opinions about what should be done with the dams before you make the final decision. as the consulting dam engineer, what do you decide to do with this dam? explain your reasoning. by making your decision, did you support the opinions of the mayor and/or the dam safety official? why or why not? (site 1)

Which part of a mountain receives the majority of moisture due to the rain shadow effect? a. the leeward side b. the windward side c. the bottom of the mountain d. all parts of the mountain receive equal amounts of moisture.

Which two following best identify the central themes of this speech in the passage the man in the arena