Do you know anything about the invention of the bar code（条形码）？

A small food store owner found it was ______ to keep records of the product information. In 1948，he asked the Drexel Institute of Technology to solve this ______.Bernard Silver，a graduate student，was interested. He and his friend Norman Joseph Woodland ______ to work on it. Soon，they invented their first working system（系统）.The system did work ______，but it was very expensive and sometimes the system didn't work well. If the invention was to become ______ in stores，the problems had to be solved. Finally，Woodland solved ______.

The patent（专利权）for the bar code system was ______ for by Silver and Woodland in 1949，but the patent was not given until 1952. ______ this patent was given，the system was still not popular among store owners.

In 1970，a business named Logicon Inc. ______ the Universal Grocery Products Identification Code（食品工业统一码）. Marsh's Supermarket in Troy was the first store to _______ this bar code reading system. It has become very popular ever since，and now it's used in all types of stores all over the world.