HOMEWORK CORRECTION:

A

There's a big bee on your nose. ✔

(Correct) 

There's are tow​​ two bees on the flower.

=> Corrected: The sentence is corrected grammatically. 

There's a butterfly on the flower. ✔​

(Correct)​

B

fire fighter ✔​

teacher ✔​ 

student​  ✔​