【正文】
t the students _________________________ (不得離開) the classroom before he returned.(leave) Ⅰ . 1. recognized 2. identity 3. government 4. present 5. actual 6. vocabulary 9. base 10. requested . recognize Ⅱ 1. play a special role in 2. was different from 3. is based on/ upon 4. make good use of 5. Believe it or not of present 8. e up some ways 三 1. be based on facts 2. play a part in 3. is increasing 4. hardly recognize it 5. should not leave