A thesis statement is a complete sentence or sentences. A thesis statement is not a question. Which of these is a strong thesis statement? Knowing a foreign language is important for people wanting to move forward in their careers. Why should people know a foreign language? Knowing a foreign language is a very useful skill that can help one advance in a career, relate better to others, and open one's mind to the ideas of another culture.

To determine which of the provided statements is a strong thesis statement, let's analyze each one based on the criteria for a thesis statement: 1. **"Knowing a foreign language is important for people wanting to move forward in their careers."** - This statement presents a clear idea but is somewhat vague. It does not specify how knowing a foreign language is important or what aspects of career advancement it relates to. 2. **"Why should people know a foreign language?"** - This is a question, not a thesis statement. A thesis statement must be a declarative sentence that presents an argument or claim. 3. **"Knowing a foreign language is a very useful skill that can help one advance in a career, relate better to others, and open one's mind to the ideas of another culture."** - This statement is strong because it clearly articulates a specific argument. It outlines three distinct benefits of knowing a foreign language, which can be further developed in the body of an essay. Based on this analysis, the strongest thesis statement is: **"Knowing a foreign language is a very useful skill that can help one advance in a career, relate better to others, and open one's mind to the ideas of another culture."** This statement is clear, specific, and provides a roadmap for the arguments that will follow in the essay.