Which statement describes the formation of galaxies?

A. They begin in nebulas.

B. Heat and gases contract.

C. Gravity causes stars to cluster.

D. Dust and gases contract.

A parabola has a vertex at the origin at (0,0). The equation of the directrix of the parabola is x=-4 In which direction does the parabola open? A) Up B) Down C) Right D) Left

Transport functions of blood include transport of hormones, hemoglobin transport of oxygen, and

What is the function of enzymes in biological systems

Steel is formed when a little bit of carbon is added to this element. (the carbon gives strenth and hardness to steel

Your county is considering the purchase of land to form a nature preserve. This land is known as a breeding habitat for an endangered species of bird.

What the surface temperature of the stars classify as white dwarfs be classified higheror lower than that of the stars classified as supergiants

Living animal cells, each with a salt concentration of 1%, are placed in a solution of 30% salt. Which of the following will occur? A.

The duck-billed platypus has 52 chromosomes in its body cells. When the platypus's body cells divide by mitosis, how many chromosomes will each daughter cell have?

What is a prokaryotes in biolog

Which of the following does not represent conditions believed by scientists to have been present on early Earth? A. An atmosphere thick with water vapor B. energy in the form of ultraviolet radiation C. extremely cold temperatures D.