13. If he (have) ___________ a temperature, he (see) __________ the doctor.
14. If my friends (come) ____________, I (be) ___________ very happy.
15. IF she (earn) ___________ a lot of money, she (fly) ___________ to New York.
16. If we (travel) ____________ to London, we (visit) ____________ the museums.
17. If you (wear) ____________ sandals in the mountains, you (slip) ____________ on the rocks.
18. If Rita (forget) _____________ her homework, the teacher (give) _________ her low mark.
19. If they (go) _____________ to the disco, they (listen) ____________ to loud music.
20. If you (wait) ___________ a minute, I (ask) ___________ my parents