spend money是spend money on doing sth 还是spend money in doing sth?我们老师讲的on doing sth 我的意思是in/on 能不能互换？

spend money是spend money on doing sth 还是spend money in doing sth?我们老师讲的on doing sth 我的意思是in/on 能不能互换？
spend money
是spend money on doing sth 还是spend money in doing sth?
我们老师讲的on doing sth
我的意思是in/on 能不能互换？

spend money是spend money on doing sth 还是spend money in doing sth?我们老师讲的on doing sth 我的意思是in/on 能不能互换？
sb spend time/mone on sth
[in]doing sth
with sb

是 in doing sth
on sth

spend money on sth
spend money (in)doing sth

spend ...(money) in doing sth.(buying CDs)
spend ...(moeny)on sth.(CDs)
* in 可以省略
spend 可加动词ing形式也可直接加名词。

spend money on sth:花费金钱购买某物
spend money in doing sth：花费金钱做某事

两种说法都对，如
I spent ten yuan on the book.
I spent ten yuan in buying the book.(in可省略）

in doing sth
on sth