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Beep! Beep! Beep! The barcode（条形码）technology makes it faster and easier to buy things in stores. You have probably seen the black-and-white barcode on 1． (product) packaging（外包装）. In 2022, the great invention is 51 years old.

In 1971, an IBM engineer named George Laurer 2． (come) up with a code（代码）that could be printed on food packages. Then, a complete code system（系统）, the barcode was formed later. The system was used by many 3． (company) from 1973. Before this, shopkeepers had to 4． (record) prices by hand which took much time and energy.

Actually, a barcode is 5． (real) a simple idea: show each product’s information in different numbers（just like the ID card number）, then 6． (include) these numbers into a code and print it for computers to read. Today, barcodes are scanned（扫描）over six billion times every day and used by two 7． (million) companies.

What information does a barcode carry? Where the product comes from, 8． (it) price, production date…It can also help stores always 9． (know) about their products. For example, if there are 10 boxes of milk and a customer buys one, it will be recorded so that the store owner knows there are nine boxes 10． (leave) on the shelf. In the 1980s, libraries started to use barcodes to follow their books in this way.