Question:
Depends on how you define "extreme".

What is a sentence that would be (on a scale from 0 to 5) a 5 out of 5 in terms of textual similarity to the above sentence?

Answer:
It depends how you define extreme.

Question:
A black faced sheep.

What is a sentence that would be (on a scale from 0 to 5) a 3 out of 5 in terms of textual similarity to the above sentence?

Answer:
A field of black faced sheep.

Question:
S Korea opposition candidate closes poll gap

What is a sentence that would be (on a scale from 0 to 5) a 1 out of 5 in terms of textual similarity to the above sentence?

Answer:
RF FM urges Syrian opposition to assist in immediate release of all foreigners captured in Syria