语法总结
want to be 表达职业理想
want to be + 职业，表示‘想成为……’；职业前通常有 a/an。
例：She wants to be an artist.
because 说明原因
Why? 用 Because 引出原因，because 后接完整句子。
例：Why do you want to be a doctor? Because I want to help sick people.
want to be + 职业
表达职业理想用 want to be + a/an + 职业名词；主语为 he/she 时 want 要变为 wants。
例：Peter wants to be a pilot. Alice wants to be an artist.
Why? Because ...
Why 用来询问原因，回答用 Because + 完整句子。
例：Why do you want to be a pilot? Because I like flying.
be good at + 名词或动名词
at 是介词，后面接名词、代词或动词-ing，不能直接接动词原形。
例：She is good at drawing. He is good at sports.