根据下面资料，回答题
What are the zebra stripes on the tomato soup cans and potato chip bags? They are special black and white vertical lines. These black and white (21)_____can be read by an optical scanner, or computer. The "scanner," which (22)_____ the lines of code, is a small laser beam of light. When the light ray is broken by the black stripes, the computer "reads" the infor-mation about the product.
This code is (23) _____the Universal Product Code (UPC). It is designed (24)_____add speed and efficiency to stores by using computers. It can do this in (25)_____ ways.
First, it is not necessary for workers to put individual prices on items. (26) _____using UPC,the computer can print out the accurate price of the item. Errors in prices are eliminated, or done(27) _____with. Also, the time spent checking out is reduced. (28) _____gives an item-ized receipt to the customer (29) _____all the items, prices, and totals. The store clerk does not need to spend time checking the price on the item and punching it into the cash register. This UPC computerized system will probably save as (30) _____ as 45 percent of the checkout clerk´ s time.
What do the stripes mean? How does the computer interpret the stripes? The number (31)_____below the vertical bars identifies the manufacturer and the manufacturer´ s item. As many as 10 tril-lion individual machine-readable numbers can be used with this system. In the example, the 0 on the left side means that it is a grocery item. The (32)_____ 51000 indicate the manufacturer.
In this case it is the Campbell Soup Company. The (33)_____ five digits,00011, mean it is a can of tomato soup. The light rays from the light beam read these lines, and the message is sent di-rectly to the computer. The computer (34) _____ finds the information about this product (price, inventory data) and sends it instantly back to the terminal (35) _____the checkout counter. At the same time, it keeps an inventory for the store manager. Many products have labels with these stripes.
第21题答案