题目

阅读理解 Roboticists at the University of California San Diego have developed an affordable, easy to use system to track the location of flexible surgical robots inside the human body. The system performs as well as current state of the art methods, but the whole system, including the robot, magnets and magnet localization setup, costs around $100. Many current methods also require exposure to radiation, while this system does not. The system was developed by Tania Morimoto, a professor of mechanical engineering at the Jacobs School of Engineering at UC San Diego, and mechanical engineering Ph. D. student Connor Watson. "Continuum medical robots work really well in highly constrained (受限的) environments inside the body," Morimoto said. "But it becomes a lot harder to track their location and their shape inside the body." The researchers used existing magnet localization methods, which work very much like GPS, to develop a computer model that predicts the robot's location. GPS satellites ping (发送) smartphones and based on how long it takes for the signal to arrive, the GPS receiver in the smartphone can determine where the cell phone is. Similarly, researchers know how strong the magnetic field should be around the magnet placed in the robot. They rely on four sensors that are carefully spaced around the area where the robot operates to measure the magnetic field strength. Based on how strong the field is, they are able to determine where the tip of the robot is. Morimoto and Watson went a step further. They then trained a neural network to learn the difference between what the sensors were reading and what the model said the sensors should be reading. As a result, they improved localization accuracy to track the tip of the robot. "Ideally we are hoping that our localization tools can help improve these kinds of growing robot technologies. We do want to push this research forward so that we can test our system in a clinical setting and eventually translate it into clinical use," Morimoto said. （1） What be learnt about the system according to the text? A . It's complex. B . It's low-cost. C . It's delicate. D . It's radioactive. （2） What is Paragraph 4 mainly about? A . The system's working principle. B . The function of GPS satellites. C . The reason for inventing the system, D . The necessity of inventing the system. （3） What do Morimoto and Watson expect of the system? A . It'll be environmentally-friendly. B . It'll be sold on the Internet soon, C . I'll be easy for us to operate. D . It'll be tested with real patients. （4） Where is this text most likely from? A . A diary. B . A guidebook. C . A magazine. D . A novel. 答案： B A D C

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