Without advanced propulsion systems, intergalactic travel remains a distant dream.

没有先进的推进系统，跨星系旅行仍是遥远的梦想。

同一单元的其他句子

• Science fiction often explores the impact of advanced technology on society.科幻小说常常探讨先进技术对社会的影响。
• Can you imagine a world where humans live on Mars?你能想象人类生活在火星上的世界吗？
• The robots in that movie were designed to serve humanity, not to replace it.那部电影中的机器人被设计来服务人类，而不是取代人类。
• Don't underestimate the power of artificial intelligence in shaping our future.不要低估人工智能塑造我们未来的力量。
• Time travel remains a fascinating concept in science fiction literature.时间旅行在科幻文学中仍然是一个迷人的概念。