spend后面到底是加in还是on？

spend on

spend ... in doing something
spend ... on something

spend on + 名词
spend in +动名词

spend in + 动词（此处的in可以省略）
spend on +名词

spend .... （in） doing sth
spend .... on sth

spend的用法:
spend past tense and past participle spent
1money [intransitive and transitive] to use your money to pay for goods or services:
I can't afford to spend any more money this week.
spend £5/$10 etc
I only want to spend about $20.
spend something on something
More money should be spent on education.
spend something on somebody
Mum never spends any money on herself.
The repairs cost a lot, but it's money well spent (=a sensible way of spending money).
2time [transitive] to use time doing a particular thing or pass time in a particular place
spend time etc with somebody
I want to spend more time with my family.
spend time etc in/at something
We'll have to spend