What are words 里的 words不可以直接翻译为：什么是诺言
one's （某人）words 才可以翻译为诺言，例如：
You have my word = I promise 我保证，我承诺，我答应，
He give you his word it will never happen again. = I promise it will never happen again.
他保证这不会再发生。
什么是诺言应该译为：
What is a promise (单数)， 或 What are promises (复数)
