Finding mistake

[Duc]

Hello everyone,
I have just done a finding-mistake exercise.It's about a man who was struck by a lightning when standing in the rain.There is a mistake in that I didn't understand very clearly,Here it is:''...When his wife enter ,he saw her FOR the first time for nine years...''
The preposition ''For'' in the above sentence must be changed to ''IN'' but I think it also sounds good with ''For'' ,of course it sounds good but may be a grammatical error.
Please explain it for me.
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Don't see your shade think you are great

[Lost_Soul]

Hi, Duc
You got it all wrong You need to change the second "for" to "in":

When his wife entered ,he saw her FOR the first time in nine years

[Duc]

Ohhhh,thank you very much
I also think the second ''for'' should be changed,not the first one because first I did change like you.
Now I feel very confident of my answer.You know, my teacher is a conservative woman (old people are usually more conservative than young people ) ,she said the correct answer must be the first FOR ,maybe there is a typo in her book but she didn't think so
_________________
Don't see your shade think you are great

[Mister Micawber]

.
Lost soul's version is correct; the book must be wrong.
.
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Native English teacher at Mister Micawber's