本期节目的问题. I am Michael from China. I'm confused with the two groups of words ''emperor/empress" and ''king/queen''. Could you point out the differences among them for me?

从1925年Beautyrest甜梦系列问世至今,它不仅成为床垫行业的里程碑产品,更代表着Simmons席梦思对人类高品质睡眠的不懈探索,和守护甜美酣眠的长期坚持。这一革命性床垫的诞生,标志着大众睡眠观念与生活方式的进阶革新,秉承“匠心铸就,梦想美眠 ...