A team of researchers recently created a robot that can repair itself. The newly designed machine can sense injury to itself and adapt. That ability sets the new robot apart from earlier machines. Because the robot can recover from unexpected damage, it may be especially useful in exploring unfamiliar places. “There is a need for planetary robotic rovers(流浪者) to be able to fix things on their own,” says Josh Bongard, one of the device’s creators. “Robots on other planets must be able to continue their mission without human help if they are damaged and cannot communicate their problem back to Earth.”
A typical robot functions according to a computer program, but the new robot works differently. First, sensors in its four legs observe the robot’s movements and signals to its built-in computer. From the information it collects, the robot creates its own programs that allow it to adapt to different situations. For example, when the researchers shortened one of the robot’s legs, the smart machine simply adjusted its way of walking—it used three legs instead of four.
The researchers are looking for other places to put the resilient(迅速恢复) robot to work. One possible spot is the ocean floor. That dark and dangerous undersea terrain(地带) might be a good choice for a robot the scientists call the Starfish. “We never officially named the robot, but we usually refer to it as the Starfish, even though a real starfish has five rather than four legs,” says Bongard. “Also, a real starfish is much better than our robot at recovering from injury, because it can ac
tually regrow its legs.” Scientists have created robots that help humans in many ways: by exploring space, fighting fires, and even performing surgery.
1. The newly designed robot is different from the former ones because it ___________.
A. can communicat
e with people on the earth about their problems
B. works according to a certain computer program
C. can find problems itself and get used to the new environment
D. can explore unfamiliar places
2. An example is given in the second paragraph in order to explain that the new robot ___________.
A. is used to create new programs B. has typical robot functions
C. has sensors to observe its movements D. can adapt to new conditions
3. What might be the best title of the passage?
A. How does the Starfish Robot work B. Do-It-Yourself Robot Repair
C. Robots Designed to Work On Other Planets D. New Robot Helping Us In Many Ways
4. Which of the following is True about the Starfish?
A. It has more than four legs. B. It hasn’t been officially named.
C. It can regrow its legs quickly. D. It has started to work on the ocean floor.
的粗糙水平面上，它们之间用轻质弹簧连接，在A上施加一个水平向右的恒力F，两物块一起以加速度a向右做匀加速运动，此时弹簧伸长量为x；若将力的大小增大到
=2F时，两物块均以加速度
做匀加速运动，此时弹簧伸长量为
，则( )