I can't be a runnner

I was very exciting because I was a girl runner.
By the way, I had Allergy last weekend.
So, my classmates' runner be changed another girl.

I was very exciting because I was a girl runner.
By the way, I had Allergy last weekend.
So, my classmates' runner be changed another girl.

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I was very excited because I was chosen to be the runner in my class   .
However, I had an allergy last weekend.
So, my class selected another girl to be the runner.