By producing melanin (pigment), the external skin coverings protect the underlying structures from ultraviolet light's harmful rays while producing vitamin ________, which works with calcium for multiple body processes

Which of the following is true of gestational surrogacy?

A) An egg is removed from a donor mother and fertilized with the sperm from a donor father. B) The child is genetically not related to the surrogate mother. C) A surrogate mother is artificially inseminated and carries the baby to term. D) The child is genetically related to the surrogate mother as well as the donor father.

Where do model building codes require venting in hoistways to prevent mushrooming?

A. The top B. The sides C. The bottom D. The bottom and sides