请问be good at和be good in有什么区别?

be in good 在...表现良好,在...有效果 但be good in 极少作文固定短语
It has been proved to be good in practice result.实践效果良好.
To have fine political and professional quality and to be good in conduct.
有良好的政治、业务素质和良好的品行;
be good at 擅长于 ...at后面跟名词或动名词（即动词+ing）
Alex is very good at languages.擅长语言
She's good at making things.