48. Our children _______to school by bus every morning. A.take B. are taken C. have taken D. are taking 49. The boy_____ by the teacher yesterday. A. punish B. punished C. punishing D. was punished 50.Today, many serious childhood diseases _____ by early immunization. A. are preventing B. can prevent C. prevent D. can be prevented 51.Bicycles ..........................in the driveway. A. must not leave B. must not have left C. must not be left D. must not be leaving 52.The robbers ....................as they left the bank. A. caught B. are caught C. have caught D. were caught 53. That book .................. by Tom yesterday. A. was bought B. bought C. had been bought D. were bought 54. Much of the city .............. by fire in the 17th century. A. was destroyed B. is destroyed C. are destroyed D. were destroyed 55. The computer ........................used since 1945. A. are B. were C. has been D. would be 56. A new bridge ....................built across the Tra Khuc River recently. A. has B. had C. has been D. had been 57. That part of the park ...................several times this year. A. is repaired B. has repaired C. repaired D. has been repaired 58. “When ..................?” “In 1928.” A. penicillin was invented B. did penicillin invented C. was penicillin invented D. did penicillin invent 59. He got good marks at his exams because all the lessons .................. carefully by him. A. are revised B. are revising C. had been revised D. to be revised 60. The room .................. once a day. A. should clean B. should be cleaning C. should be cleaned D. should have cleaned