Jason Barnes is a young musician who lives in Georgia. Eight years ago, Jason lost his right arm just below his elbow in an accident. Jason got a prosthetic (假体的) arm. But this arm could only do a few things. Jason still wanted to play music. So he went to see Gil Weinberg, who makes musical robots. To play the piano, Jason needed five fingers that could move just the way he wanted. This was a big challenge.

Living arms move when muscles respond to commands from the brain. When you think “open fingers”, your brain sends electrical signals along nerves. Some prosthetic arms use sensors (传感器) to try to read these nerve signals. But they don’t work very well. Nerves are tiny, and their signals are faint. Sensors might be able to tell that you want to move a finger. But they aren’t very good at telling which finger you want to move.

Jason doesn’t have his hand anymore, but he still has the arm muscles that move his fingers. When Jason thinks about moving his fingers, those muscles still move. To read the muscles inside Jason’s arm, the team used ultrasound (超声波). The roboticists taught a computer to read the ultrasound sensor as Jason thought about moving his fingers. The computer learned which muscles moved when Jason wanted his fingers to move in a certain way. Thinking about moving his fingers makes the muscles in his upper arm move. The computer sees the moving muscles and tells the motors in Jason’s robotic fingers to move the right way.

The team hopes the “Skywalker hand”, their prosthesis, will someday work as well as a real hand. The sensors, motors, and computers inside the hand are not complex. But they need to get smaller and cheaper before lots of these hands can be made. Weinberg and his team are working on this right now. Soon, they hope that anyone who loses a hand will be able to get a new robotic one with five fingers that they can move just by thinking.

【小题1】Why did Jason visit Weinberg?

A．To save his own life.

B．To learn to play music.

C．To study musical robots.

D．To replace his prosthetic arm.

【小题2】What does the underlined word “faint” in paragraph 2 mean?

A．Specific.

B．Weak.

C．Stable.

D．Predictable.

【小题3】What makes the invention of the robotic hand possible?

A．Moving muscles are simpler to spot than nerves.	B．Nerve searching techniques have developed fast.
C．Ultrasound sensors vary from finger to finger.	D．Motors are much quicker to operate.

【小题4】What do Weinberg and his team expect of the Skywalker hand?

A．It’ll be easy to make.	B．It’ll be customer-friendly.
C．It’ll be better than real hands.	D．It’ll be controlled by computers.