5．
Have you ever noticed the black and white bars on a book？Do you know what they are used for？
They are barcodes used in most products．If you go to a supermarket，you can see almost every product with a barcode on it．（60）E，such as name and production date．It's an easy and convenient way to keep track of the products．（61）B．
The first use of a barcode in a supermarket checkout system was on a pack of American Wrigley Company chewing gum in 1974．Besides supermarkets，barcodes are needed everywhere：For renting cars，for luggage checks on a plane，for parcels （包裹） you send．People can enter stadiums，cinemas and theaters by holding certain types of barcodes．（62）D．
If you find these barcode things boring，a barcode building might be more up your street．In St Petersburg，Russia，there is a building designed like a barcode．It looks strange，but it's actually a shopping mall．There are games too．Barcode Monsters is a mobile phone game．（63）A．
A．You have to scan barcodes and find the monsters
B．Just scan the bars with a barcode reader and everything is clear
C．You can buy an iPhone to play the game
D．Life would be rather difficult without barcodes
E．Barcodes contain information about the products．
科学实验活动册系列答案
