21．Which of the following is TRUE according to the passage?

A．Austen was born 200 years ago.

B．Austen rewrote Pride and Prejudice.

C．Austen's success lies in her wisdom.

D．Austen's updated work gains popularity.

22．The underlined part in the passage suggests that Mrs Bennet ．

A．had mixed feelings of admiration and surprise about Bingley

B．felt kind of worried and doubtful about Bingley

C．was extremely anxious to meet Bingley

D．had a great curiosity about Bingley

23．In the eyes of Mrs. Bennet，Bingley surely needed one of their boys to ．

A．get married to　　　 B．work for her

C．help her move in D．take over her store

24．What does the writer intend to tell us?

A．Women with brains can also be as successful as men.

B．Women have to pay a high price for success.

C．A judgment must be made free from prejudice.

D．Sex discrimination still exists nowadays.

　　　　　　　　　　　　　　　　　B

Scientists in London are working to develop a wheelchair that can be moved simply by looking in the direction in which the user wishes to travel.

Most paralyzed (瘫痪的) people can still move their eyes because they are directly connected to the brain. Some existing technologies already allow severely disabled people to stare at arrows (箭头) on a computer and direct the movement of a wheelchair. But there are problems with that system，including a delay between the movement of the eyes and the wheelchair.

"Current tracking software often uses a screen­based system where you have a screen open and you look at locations on the screen. The problem with that is that it diverts (转移) the user's attention from the outside world and therefore there's more risk of not noticing other things like stones in the way，"said Kirubin Pillay，a PhD student at Imperial College London.

A team led by Aldo Faisal at Imperial College London has developed a software that allows users to move the chair just by looking in the direction they want to take.

"Our eyes are not only a window into our soul. They're also a window to our intentions. So if we want to go somewhere，we will look there in a specific manner. We can build a computer system that can decode (解码) our eye movements，and so we observe eye movements with an eye tracker，and the computer interprets these commands and drives the wheelchair accordingly，"said Fasial.

Two cameras trained on the eyes observe their movements and can determine whether a patient is merely looking around or wants to move in a certain direction.

Visual information detected by cameras is analyzed by algorithms(计算程序)and then translated into instructions for movement that's almost instantaneous(瞬间的)．

The camera­based system costs only about $85 because most of the work is done by the algorithms. No expensive hardware is needed. The London team hopes to make the system commercially available within three years.

25．One of the current tracking software's problems is ．