What are the two main factors in the mantle that contribute to the rock cycle?
A.
weathering and layering
B.
heat and weathering
C.
pressure and heat
D.
layering and pressure

What filament and tubules give a cell its shape

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.

How many moles of oxygen react with 12 moles of aluminum