IV.Read the text below and mark the letter A, B, C or D on your answer sheet to decide which answer best fits each space from 1 to 5. Most people think of computers as very modern inventions, products of our new technological age. But actually the idea for a computer had been worked out over two centuries ago by a man (1)_____ Charles Babbage. Babbage was born in 1791 and grew up to be a brilliant mathematician. He drew up plans for several calculating machines which he called "engines". But despite the fact that he (2)_____ building some of these, he never finished any of them. Over the years people have argued (3) _____ his machines would ever work. Recently, however, the Science Museum in London has finished building (4) _____ engine based on one of Babbage's designs. (5) _____ has taken six years to complete and more than four thousand parts have been specially made. Whether it works or not, the machine will be on show at a special exhibition in the Science Museum to remind people of Babbage's work. 21. A. written B. called C. recognized D. known 22. A. started B. wanted C. made D. missed 23. A. until B. though C. whether D. why 24. A. that B. the C. some D. an 25. A. He B. They C. One D. It