Evaluate the similarity between them and classify them into classes from 0-5 as follows:
0 : The two sentences are completely dissimilar.
1 : The two sentences are not equivalent, but are on the same topic.
2 : The two sentences are not equivalent, but share some details.
3 : The two sentences are roughly equivalent, but some important information differs/missing.
4 : The two sentences are mostly equivalent, but some unimportant details differ.
5 : The two sentences are completely equivalent, as they mean the same thing.

Sentence 1: The young rider takes a ride on the brown horse. Sentence 2: A young female rider on a brown horse.
4

Sentence 1: Scenario A assumes that the CO growth rate accelerates by .%/yr. Sentence 2: It assumes that methane growth rate accelerates by .%/yr.
2

Sentence 1: The man cut some carpet with a knife. Sentence 2: A man is cutting carpet with a knife.

5