Exercise 5: Rewrite the following sentences using Perfect Participle.
1. We switched off the lights before we went to bed.
2. As he had drunk too much, he didn't drive home himself.
3. We had worked in the garden all day and were sunburned in the evening.
4. Since I had not seen him for ages, I didn't recognize him.
5. I had not ridden a horse for a long time and I found it very difficult to sit on the sa