How would you describe Earth's movements? Select all that apply. A. The Earth rotates on its axis, orbits around the Sun, moves with the solar system in galactic motion, and moves through the universe with the Local Group.

B. The Earth's movements are inconsistent and too difficult for scientists to explain.

C. The Earth is always experiencing motion, and there are four primary movements.

D. The Earth is the only thing that is moving in our solar system.

Nebulae are enormous clouds in outer space. they are made mostly of hydrogen gas, helium gas, and dust. some nebulae glow brightly, while others do not. the stars that people see are huge, bright balls of glowing gas. they are made mostly of hydrogen and helium. which statement correctly describes other ways in which nebulae and stars are different? a. stars can form inside a nebula but a nebula can never be produced by any star. b. a star always has a higher density than a nebula. c. stars can never form inside a nebula but a nebula can be produced by any star. d. a nebula always has a higher density than a star.