Respuesta :
"Gerbils’ teeth grow continuously; therefore, gerbils need to chew daily to keep their teeth short."
The answer to your question would be that the sentence that is correctly punctuated is the following one: Gerbils' teeth grow continously; therefore, gerbils need to chew daily to keep their teeth short.
You should use a semicolon before "therefore" when it is introducing a complete sentence. Moreover, it is convenient to use a comma after it.
