【问】 From a heavy gun that was raised，the captain realized that the ship must have been acruiser. (New Concept English，Book 3，L.32)
 [原译]船长从一门捞起来的重炮上判断出这艘船很可能是一艘巡洋舰。
 原译文把must have been译为“很可能”，是否准确?
 【答】 may+完成时不定式与must+完成时不定式所表达的意思是不同的。前者表示从现在看来过去可能发生过某事，而后者表示“逻辑上的必然性”，即说话人推断过去肯定发生过某事。请考察下面的实例及其中译文：
 1. Sam was sure that the wallet must have been found by one of the villagers，but it wasnot returned to him. (New Concept English，Book 2，L.45)
 萨姆肯定钱包是让一个村民拾去了，但是没有人还给他。
 2. The city at one time must have been prosperous，for it enjoyed a high level of civiliza-tion. (New Concept English，Book 3，L.3)
 这座古城肯定一度很繁荣，因为它享有高度的文明。
 3. He must have gone to the clinic.(PEG²)
 他一定是去医务室了。
 4. You may have read about it in the papers.(PEG²)
 你可能已经在报纸上读到这件事了。
 5. He may have missed the train.(CGEL)
 他可能没有赶上火车。
 请做下面的英语试题：
 1. “Was that the dean who walked by?” “____. ”
 A. It must be that B. It must have been
 C. He must be it D. Must have been it (TOEFL，70. 6)
 2. It is cold in the room. They____have turned off the steam.
 A.mustB.oughttoC.shouldD.could(攻读硕士学位研究生入学考试英 语试题，83B)
 3. An ambulance was waiting in the street，somebody____hurt or killed.
 A. should have been B. should be
 C. must have been D. should not have been
 4. “The streets are all wet. ” “It____during the night.”
 A. must be raining B. must have been rain
 C. had to rain D. must have rained(TOEFL，71.10)
 5. “Why didn’t you answer the phone last night?”
 “I____when you called. ”
 A. had to have slept B. have to be sleeping
 C. must have been sleeping D. must have slept (TOEFL，75.5;75.9)
 6. Since the ground is white it____last night.
 A. had snowed B. must have snowed
 C. must snow D. must have been snow.(攻读硕士学位研究生入学考试英语试题，81B)
 7. My pain______apparent the moment I walked into the room，for the first man I metasked sympathetically： “Are you feeling all right?”
 A. must be B. had been
 C. must have been D. had to be(攻读硕士学位研究生入学考试英语试题，96)
 8. I didn't hear the phone. I________ asleep.
 A. must be B. must have been
 C. should be D. should have been(全国高考英语试题，1989)