30. A. existence 　 　 B. invention 　　　 C. usage 　　　　 D. practice

29. A. known 　　　 B. unknown 　　　　 C. worked out 　 　　　 D. not worked out

28. A. where 　　 B. that 　　　　 C. when 　　　　 D. which

27. A. but 　　　 　　　 B. however 　　 C. though 　　 　　 D. therefore

26. A. asking 　　 B. producing 　　 C. testing 　　 　　　 D. hiring

25. A. work 　　　 B. university 　 C. custom 　　 　 D. question

24. A. raise 　　　 B. answer 　　 C. talk 　　　 　　 D. discuss

23. A. working 　　 B. asking 　　　　 C. looking 　　 　　 D. waiting

22. A. considered 　 　　　 B. enjoyed　　 C. suggested 　 　　　 D. included

In ancient times, the most important exams were spoken, not written. In the 　21　 of ancient Greece and Rome, testing usually 　22　 saying poetry aloud or giving speeches. 　In the European universities of the Middle Ages, students who were 　23　 for advanced degrees had to 　24　 questions in their field of study with people who had made a special study of the subject. This 　25　 exists today as part of the process of 　26　 candidates (应试者) for the doctor's degree. 　Generally, 　27　, modern exams are written. The written exam, 　28　 all students are tested on the same questions, was probably 　29　 until the nineteenth century. Perhaps it came into 　30　 with the great 　31　 in population and the great development of modern industry. A room full of candidates for a state exam, 　32　 exactly by electric clocks and carefully watched over by managers, is similar to a group of 　33　 at an automobile factory. Certainly, during exams teachers and students are 　34　 to act like machines. 　One type of test is sometimes 　35　 an "objective(客观题) test". It is intended to deal with facts, not 　36　 opinions. To 　37　 an objective test the teacher writes a series of questions, each of which has 　38　 one correct answer. Along with each question, the teacher writes the correct answer and also three statements that 　39　 answers to students who have not learned the material 　40　.

21. A. governments 　 B. schools 　　 C. homes 　　　　　 D. offices