C Example: If he (come) yesterday, he would have helped us. — If he had come yesterday, he would have helped us.
1. She (notice) this mistake if she had been more attentive. 2,1 might have gone on an excursion with you if I (know) about it beforehand. 3. If we (know) that you were there, we would have called on you. 4. If I had known of his arrival, I (meet) him. 5. Nobody told me about your trouble. I would have helped you if I (know) about it. 6. If you had tried your best, you (get) the job. 7. If he (not work) late, he would have caught his bus. 8. If Mary had agreed to sit in for us, we (go) to the movie yesterday. 9. He (pass) his exams well if he had studied hard. 10 Л would have prepared everything yesterday if I (receive) your message on Monday.