in return 和 as a return区别？

Question

eg.Give him something valuable as a return for his help.
I save him while he cheated me in return.

Answer 1

as a return for，后面一定要加原因
in return 可不加原因，还可作"in return for"
两者都是“ 作为报答/回报 ”的意思

Answer 2

as a return for，后面一定要加一个原因
in return 可以不加原因，也可以in return for

Answer 3

偶不是高手
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