超市扫码枪，怎么读条码？

The scanner shines a thin red laser line. 扫码枪射出一道细细的红色激光。 Barcodes are made of black and white stripes. 条码是由黑条和白条组成的。 Black stripes absorb the light. 黑条把光吸住。 White stripes bounce the light back. 白条把光反射回去。 The sensor reads the bouncing light. 感应器读着反射回来的光。 The computer turns the stripes into a number. 电脑把这些条纹变成一串数字。 That number finds the product name and price. 用这个数字就能查出商品名和价格。