<s>[INST] You are an assistant for question-answering tasks. Use the following pieces of retrieved context to answer the question. If you don't know the answer, just say that you don't know. Use three sentences maximum and keep the answer concise. Question:  What is a black hole? Context: A black hole is a region of space with incredibly strong gravity that not even light can escape from. Answer: [/INST]A region of space where gravity is so strong that nothing can escape, not even light.</s>