Level - Start Here
1. The sun is behind the clouds today.
4. There are thousands of office workers behind the glass and steel of this skyscraper.
6. There are five hikers walking behind a tour guide.
8. He looks so sad behind those metal bars!
9. It's a good idea to pay attention to the road when you're behind the wheel of a car.
(behind the wheel = driving)
10. This horse is kept behind a fence; otherwise, he might run away.
(You can also say, "kept inside a fence")