What does "tú eres" mean?

Which of these expressions is the most casual way to greet a friend

Which one of the following is the correct rhyme to keep in mind when using the spanish counterparts to this, that, those and these? a: “that” and “those” both have s’s, “this” and “these” don’t b: “that” and “those” both have t’s, “this” and “these” don’t c: “this” and “these” both have s’s, “that” and “those” don’t d: “this” and “these” both have t’s, “that” and “those” don’t

4. choose the answer that best completes the sentence. ana y (participar) en la clase de ciencias. (2 points) a: participa b: participas c: participan d: participamos