1. They often clean their classroom after school . (改为被动语态)

　　 Their classroom _____ often ______ by them after school.

8. When was invented the bicycle ? ____________________

7. Somebody broke into our house but nothing stolen. ____________________

6. How many languages are speaking in Switzerland ? ____________________

5. Where are you born ? ____________________

4. A garage is a place where cars repair. ____________________

3. Why did the letter send to the wrong address ? ____________________

2. Football plays in most countries of the world. ____________________

1. This house built 100 years ago . This house was built

8. (I / not / wake up / by the noise )_________________________