Answer:
The answer to your question is simultaneous. Hope it helps!
Organ system, because there are multiple organs that work together to help make the body function.
A beaker of black powder can be a mixture with different substances (i.e gunpowder: a mixture of sulfur, charcoal, etc.), an element which can probably be carbon (known as black), and a compound as well which can be potassium nitrate. Hence, the answer is D.
Nonmetals and negative. Answer is c
10 miles per hour because 500 divided by 50 is 10
