What's meaning of the word "middle children"?

What's meaning of the word "middle children"? What‘s meaning of the word “impressive” what's the meaning of this word ? what's the meaning of the word?（同义句） What's the meaning of the underlined word fantastic "What's the meaning of the word 'drunk',dad? What's the chinese meaning of the underlined word"custom"? .What's the meaning of the underlined word "fantastic"? What's the meaning of the word同义句转换 what's the meaning of this word "burning" in Chinese? 英语翻译是除了what's the meaning of the word和what does the word mea what 's the meaning of.