1. David had gone home before we arrived.

  → After David had gone home, we arrived.

2. The teacher explains the lesson.

  → The lesson is explained by the teacher.

3. They have provided the victims with food and clothing. 

  → They victims have been provided with food and clothing.

4. If you don't work hard, you will get bad works.

  → Unless work hard, you won't get good marks.

5. Because his bike was broken, he arried late forr the concert.

  → Because of his broken bike, he arrived late for the concert.

1.After David had gone home, we arrived.

2.The lesson is explained by the teacher.

3.The victims have been provided with food and clothing.

4.Unless you work hard, you will get bad works.

5.Because of his broken bike, he arrived late for the concert.