Final answer:
Yes, 'No' can be a sentence-level negation in natural language.
Step-by-step explanation:
Yes, "No" can be a sentence-level negation in natural language. In natural language, sentence-level negation is typically achieved by using negative words or phrases to express a negative meaning. For example, in the sentences "Oh, no, you don't!" and "Well, then-I am not!", the word "no" is used to negate the idea or statement being expressed. These examples illustrate how "no" can function as a sentence-level negation in natural language.