which substance is harmful to the body when consumed (A) calcium (B) Cobalt chloride (C) iron (D) phosphorus (E) sodium chloride​

Which mantle is under the crust the upper mantle or the lower mantle i think it's upper let me know if i'm right

Groups of organisms with low biotic potential, such as gray whales, that produce at most one offspring every other year a) are r-selected b) are k-selected c) are not subject to density-dependent limiting factors d) show the initial stages of the extinction process e) have escaped from the processes of natural selection and adaptation

Astudent observes a star from two positions of earth in its orbit, in summer and winter, and measures the change in the position of the star. which of these can be best calculated by this method?