单选题 Electronic computers, ______ the complicated mathematical operations, such as weather forecast and the control of satellites, can be done quickly and accurately.
  • A. being used
  • B. used
  • C. having been used
  • D. to be used
【正确答案】 C
【答案解析】分词短语在此处作原因状语,使用了计算机才能进行又快又准确的运算,两者之间有个先后关系,所以要用完成式表示使用计算机发生在先。题句意为:“由于使用了计算机,像天气预报和卫星控制之类复杂的数学运算可以完成得又快又准确。”