As is known to us, theory is based on practice and _____ servers practice. A. by chance B. in turn C. in return C. by turn
58. Though his classmates are all ahead of him, he is studying very hard to _____ them.
57. Yesterday I was in the rain on my way back home, and I got a bad could and coughed very badly.
56. The shopkeeper _____ the tramp(流浪汉) stealing sweets from the new supermarket and _____ him.
55. I can’t see John anywhere. Where _____ he have gone?
54. Extensive tests have been on the patient.