2. 外语
  3. The marvel of the machine age, the electronic computer has been【C1】______only since 1946. It can do simple computations — add, s

The marvel of the machine age, the electronic computer has been【C1】______only since 1946. It can do simple computations — add, s

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问题     The marvel of the machine age, the electronic computer has been【C1】______only since 1946. It can do simple computations — add, subtract, multiply and divide —【C2】______lighting speed and perfect accuracy. It can multiply two 1-digit number in 1/1, 1000 seconds, a problem that would【C3】______an average person five minutes to do with pencil and paper. Some computers can work 500, 000 times faster than【C4】______.
    Once it is given a "program" — that is, a【C5】______set of instructions devised by a technician trained in computer language — a computer can gather【C6】______information for many purposes. For example, it can【C7】______bank accounts up to date and make out electric bills. If you are planning a trip by plane, the computer will find out【C8】______route to take. Not only can the computer gather facts, it can also store them as fast as they are gathered and can【C9】______whenever they are needed. 【C10】______gathering and storing information, the computer can also solve complicated problems that once took months for people to do.
    For example, 【C11】______sixteen hours an electronic brain solved a difficult design problem. First, it was【C12】______all the information necessary for designing a chemical plant. After running through 16, 000 possible designs, it【C13】______the plan for the plant that would produce the most chemical at the lowest cost. Then it issued a printed set of exact【C14】______. Before it solved this problem, a team of engineers having the same information had worked for a year to produce only three designs, 【C15】______of which was as efficient as the computer’s.
【C1】
选项 A、using
B、in use
C、being used
D、used
答案B
解析 语法知识。根据句中的时间状语since 1946判定，句子的时态应为现在完成时，排除选项A和C。句子强调的是在1946年就“开始”使用了，in use为固定短语，意为“在使用中”。故答案为B。
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