单选题 In the 1880's, Engineer Herman Hollerith was given a job by the American government to make an official count of the country's total population, which is now called census. Mr. Hollerith worked hard to search for a way to record the census information of America, and found it on a train, where he saw a conductor using some tool to make holes in tickets. The position of each hole told something about the ticket holder (持有人) , such as hair or eye color. If the "passenger' turned out to be a train robber, this record would help the pollce catch the criminal. What he saw on the train greatly inspired him to invent a machine which could calculate like an abacus. Hollerith designed punched (打过孔的) cards for an electric computering machine, for each hole gave the answer to a question, and the machine counted the holes. Thus, the great grandfather of the modern computer was born.

单选题 This passage mainly discusses how ______.
【正确答案】 A
【答案解析】文章的中心是讲Hollerith如何受到火车售票员的启发因而发明打孔计算器的。所以答案选A。
单选题 The machine discussed in this passage was the ancestor (祖先) of today's ______.
【正确答案】 D
【答案解析】文章倒数第一句提到，Thus，the great grandfather of the modern computer was born．暗示了它就是计算机的雏形。
单选题 According to this passage, holes were made in train tickets so as to______.
【正确答案】 B
【答案解析】文章提到，The position of each hole told something about the ticket holder，such as hair or eye color。B选项正是这句话的改写。