They are asked to write a paper about＿＿＿they want to be when they grow up.这里为什么要用what...
问题描述：
They are asked to write a paper about＿＿＿they want to be when they grow up.这里为什么要用what...
They are asked to write a paper about＿＿＿they want to be when they grow up.这里为什么要用what,而不用whoever?
答
他们被要求写下 当他们长大时 想要成为什么样的人（或想要做什么【工作】）.
什么样的人 而不是 想要成为 谁
所以用 what
例如 what is he?他是做什么的.