Speaking from experience, the answer is not D.
The thermal energy produces warmth against the cold rocks causing them to break
The Arctic Ocean is the shallowest ocean in the world.
Answer:
Explanation:

Now for some explanations.
- sqrt(90)/sqrt(20) can be put under 1 square root sign.
- When you do that, 10 divides into both numerator and denominator.
- The sqrt(9) = 3
- The square root of 2 cannot be reduced, but you can rationalize it by multiplying top and bottom by sqrt(2)
3 sqrt(2)
======
sqrt(2)*sqrt(2)
Answer
3 * sqrt(2)
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2