The invention of barcodes(条形码) is based on a very simple idea. We only need to give each product a specific number and print it. (9)It can simply print the number itself. But this can cause problems. For example, an unclearly printed "seven" could look like a "one" to a computer. It's also true for "three" and "eight". (10)We need a better way of printing numbers so that they can be read correctly at high speeds. That's the problem barcodes solve.
Each number in a barcode is shown by seven blocks of the same size. (11)For example, the number "one" is shown in turn by two white stripes(线条), two black stripes, two white stripes, and one black stripe. (12)
A barcode includes different parts and each one provides a specific meaning. The first part of a barcode tells you the country where the product was made. For example, 690-692 is the barcode for China. (13)The final part is about the product itself. This is how barcodes work.

Ⅲ. 词汇运用
阅读下面的短文,在空白处填入1个适当的单词或用括号内所给单词的正确形式填空。
Last Friday, a special event took place at the National Theatre of Korea. A robot called EveR 6 led an orchestra(管弦乐队) in performance of Korean music. Robots have led orchestras in other countries, but this was the time ever in South Korea.
EveR 6 is about as tall as a person, and has a human-like face that can show feelings. It can move arms quickly and smoothly in many different directions.
In Friday's performance, the National Orchestra of Korea a concert titled "Absence". The concert included five different pieces of music. Every movement of the robot's arms brought instruments into the mix, and the orchestra's music grew louder and more exciting.
Mr Choi was impressed with the way EveR 6 moved. "The robot was able to present such detailed moves much better I had imagined," he said.
But the robot still is not nearly ready to replace a human conductor. Mr Choi says the robot's greatest weakness is that it can't hear. "Some people think that conducting (指挥) is just a combination(组合) of hand waving and the beat," says Mr Choi. But a good conductor needs to listen to the orchestra , so that he or she can correct and encourage the orchestra as it plays.
Mr Choi said that once EveR 6 started, the musicians had "no choice but its beats." Mr Choi doesn't think robots are likely to replace human conductors. he believes robots could be helpful in situations like practice music where the same thing needs to be repeated many times.