The word settled is used correctly in that sentence. If there are more sentences comment them I can help.
Answer:
An endangered language, or moribund language, is a language that is at risk of falling out of use as its speakers die out or shift to speaking another language. Language loss occurs when the language has no more native speakers and becomes a "dead language".
Explanation:
I dont think i can answer the first few, but i can answer 4. and 5.
For number 4. it is 'The ferocious lion roared at the helpless zebra'
And for number 5. it is 'Study how to brush and shoe horses'
Hope this helps you!