I. 填入适当的引导词
1. I havent heard from him _____ he went to America. 2. He wont be here _____ he is invited.
3. He will not go to the cinema _____ he is very busy. 4. We found the key _____ she lad left it.
5. We found the books two days ____ he had gone away. 6. We had no sooner got to the station _____ the train left.
7. He speaks English ______ he were an Englishman. 8. He is explaining clearly _______ they could understand.
9. Do not leave the room _____ you have finished the test. 10. She sang ______ she went along.