Put the verbs in brackets into the correct tense

[natali]

Sarah is a bored teenager. If she …. joined… (join) a club, she ……………………… (make)
more friends. She ………………………………. (enjoy) herself if she …………………….. (go)
out more. Her schoolwork is suffering too. If she ………………………………….. (study) more,
she ………………………………….. (have) better marks and she ………………………. (enter)
university. Unfortunately, she is becoming overweight. She ………………………………. (feel)
fitter if she ……………………………….. (start) swimming, and she …………………….. (get)
thinner if she ……………………………… (stop) eating so much chocolate.