<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>
The earth is surrounded by <em>a layer of</em> gases called the <em>atmosphere</em>. The atmosphere is very <em>important </em>to life on <em>Earth</em> and does many <em>things</em> to help protect life and help<em> life </em>to survive.
The atmosphere absorbs the <em>heat</em> from the <em>Sun </em>and keeps the heat <em>inside</em> the atmosphere helping the <em>Earth </em>to stay warm, called the <em>Greenhouse </em>Effect.
Answer:
The first picture is the best example of plant tissue.
Explanation:
Thank u and I hope this helps ;)
Answer:
Warm air is cooling quickly.
Explanation:
Hot air rises and cool air sinks.
Answer:
Biologists measure the number of trophic levels in an ecosystem so as to check its stability and health.
Explanation:
Trophic levels are the feeding position in a food chain such as primary producers, consumers, etc. They are positions that an organisms occupies in a food chain (series of steps in which organisms transfer energy by eating or being eaten);- what it eats and what eats it.
Theoretically there is no any limit to the number of trophic levels in a food chain or number of organisms that live on each level.