Forpheus

　　Forpheus, an "athletic" robot developed by Japanese technology company Omron. It teaches users how to play ping-pong. The 10-feet-tall machine uses a camera and artificial intelligence to track the ball's speed and can predict the ball's direction correctly. The smart Forpheus can also quickly test its player's abilities and adjust the playing level, making the game fun.

Black Box VR

　　Though many people determine to go to the gym once a week, few reach their goal. Black Box VR wants to change that by turning hard exercise into fun video games. Using it, gym users will find themselves fighting enemies, including big creatures-all while getting exercise.

21. What is the feature of CX-1?

　A. It can be opened by facial expressions.

　B. It can recognize and follow its owner.

　C. It can move very fast in busy places.

　D. It can sense the suitcase's location.

22. Who would most probably want an Aibo?

　A. People who want to walk a dog.

　B. People who often play tricks on others.

　C. People who want to take high-quality photographs.

　D. People who want a dog but can't look after a real one.

23. Which product can help people do physical exercise regularly?

　A. CX-1. B. Aibo. C. Forpheus. D. Black Box VR.

　　Are you carrying too much on your back at school? I'm sure lots of children of your age will say "Yes". Not only do the students in China have this problem, but children in the United States also have heavy school bags.

　　Doctors are starting to worry that younger and younger students are having back and neck problems as a result of school bags being too heavy for them.

　　"It's hard for me to go upstairs with my bag because it's so heavy," said Rick Hammond, an 11-year-old student in the US.

　　Rick is among students who have common school bags with two straps (带子) to carry them, but many other students choose rolling bags.

　　But even with rolling bags, getting upstairs and buses is still a problem for children. Many of them have hurt their backs or necks because of the heavy school bags.

But how much is too much? Doctors say students should carry no more than 10% to 15% of their