10．
完形填空。
Do you know anything about the invention of the bar code（条形码）?
A small food store owner found it was 1 to keep records of the product information. In 1948, he asked the Drexel Institute of Technology to solve this 2. Bernard Silver, a graduate student, was 3. He and his friend Norman Joseph Woodland 4 to work on it. 5, they invented their first working system.
The system did work 6, but it was very expensive and 7 the system didn't work well. If the invention was to become 8 in stores, the problems had to be solved. Finally, Woodland solved 9.
The patent（专利权） for the bar code system was 10 for by Silver and Woodland in 1949, but the patent was not given until 1952. 11 this patent was given, the system was still not popular 12 store owners.
In 1970, a business named Logicon Inc. 13 the Universal Grocery Products Identification Code（食品工业统一码）. Marsh Supermarket in Troy was the first store to 14 this bar code reading system. It has become very popular ever since, and now it's 15 in all types of stores all over the world.
