<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>
I just did it and got it correct the answer is inside the circle which is the first one. Good luck on the questions.
1.chloroplasts
2. Centriole
3.membrane
4 clotoplasm
7 mitochondria
8 cellulose
10 ribosome
11 vacuoles
12 cytoplasm
13 chromatin
14 diffusion
15. I'm not sure sorry