D is the best answer
(I am just using my common sense)
Hope I helped :)
Answer:
The Ar-Rub al Khali desert is well known as Rub' al Khali desert. It is also known as Empty Quarter of the Saudi. It is located in the Saudi Arab and is one of the largest desert of the world. It has an area of about 250,000 miles square.
Explanation:
Adding an enzyme inhibitor to a reaction catalyze by an enzyme
I can’t see the choices, but the main part of having valves within the heart and veins it to pump blood throughout the body
