Write these sentences in full, using the words given. Put the

Write these sentences in full, using the words given. Put the verbs in the correct tense. Third conditional mood.
1) I / not / marry / him / if / I / know / what he was like.
2) I / not / hire / a car / if / I / know / how expensive it was.
3) If / we / got / to the cinema earlier / we / not / miss / the start of the film.
4) If / I / be born / a year earlier / I / have to do / military service.
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If possible from your side, explain how to build sentences with the third conditional tense, what rules you need to apply. I hope for your help. Thanks in advance!