1. The children were running on the playground as fast as they can .

10. She sang ______ she went along .

答案： 1.since 2.unless 3.because 4.where 5.after 6.than 7.as if　 8.so that　 9.before 10.as

9. Do not leave the room _____ you have finished the test .

8.He is explaining clearly _______ they could understand .

7. He　 speaks English ______ he were an Englishman .

6. We had no sooner got to the station _____ the train left .

5. We found the books two days ____ he had gone away .

4. We found the key _____ she lad left it .

3. He will not go to the cinema _____ he is very busy .

2.He won't be here _____ he is invited .