1. If you (were) busy, I (would leave) you alone.
2. If my friend (came) to see me, I (would be) very glad.
3. If mother (bought) a cake, we (would have) a very nice tea party.
4. If we received a telegram from him, we (would not.worry).
5. If you (did not work) systematically, you (would fail) the exam.