Respuesta :
The answer is, " I have always wanted to become a veterinarian but, I don't do very well in science and math classes."
Answer:
The sentence that has correct punctuation is the following one: I have always wanted to become a veterinarian, but I don't do very well in science and math classes.
Explanation:
The sentence above is the right answer because you should use a comma before the coordinating conjunction. When two independent clauses are joined with a coordinating conjunction (but, in this case), a comma is required before the conjunction. Otherwise, the sentence would become a run-on sentence.
