Допишите следующие предложения. 1. You would know English better if … 2. I should have left Moscow yesterday if … 3. If I were you, … 4. If  I had known that it was going to rain, … 5. I shall go for a walk, if … 6. I should lend you my textbook if … 7. If we had bought the tickets, … 8. If they were here, …