Which is the final event that occurs when a star is forming? O The outer layer of the star expands.
O Gravity pulls gas and dust together.
A black hole forms as the core collapses.
Nuclear fusion begins under high pressure.

Cancer cells spread to other parts of the body by entering the bloodstream. which of the following organs could prevent a cancer cell in the bloodstream from spreading, and why? a. the spleen, because it releases lymphocytes into the blood b. the peyer's patches, because they release lymphocytes into the blood c. the lymph nodes, because they release lymph into the blood d. the thymus, because it releases lymph into the blood