<span>The elements that are found in a high proportion in Earth's crust are oxygen, aluminium, iron, calcium, potassium, sodium, and magnesium. But for your Option, I think it is B) Oxygen and Silicon. This is because Oxygen makes 46.6% while Silicon makes 27.7% of the Earth crust.</span>
Answer:
D. Which cell organelles carry out the process of photosyinthesis and cellular respiration?
Coral reefs are built by coral polyps as they secrete layers of calcium carbonate beneath their bodies. And inside each coral poly lives single-celled algae called zooxanthellae. So basically in simplistic terms, coral polys create coral reefs and algae is in coral polys which also goes into coral reefs when they are made.
A maybe sounds abt right sorry if it's wrong.