阅读理解。 New technology that can ' see' through clothing and detect what 's underneath can now be used to scan crowds, making it a potentially effective tool to prevent terrorist attacks in public places. The Thru Vision T5000 camera picks up Terahertz rays,or T-rays, which are naturally sent out by all objects and can pass through clothes or even walls. The camera can then detect metallic and nonmetallic objects hidden under clothing on still or moving subjects without showing any body detail. While similar technology is seen at airports around the world, the T5000 is designed to be used in large, open areas. With a range of 25 meters, the T5000 can screen people in public places, thus avoiding bottle-necks at border crossing or security checkpoints. It also means people can be screened without knowing it. The technology develops from British astronomers ' work in studying dying stars. Astronomers use T-ray cameras to see through dust and clouds in space. The company sees uses for its camera at other sites where political or business activities take place. For privacy concerns,Thru Vision Chief Executive Clive Beattie said the image produced by the camera did not show detailed parts of the body.' It's almost a shining light bulb (灯泡).' Beattie said. 'You don' t see the detail that people might be concerned about.' In London' s busy Piccadilly Circus-which is already filled with closed-circuit surveillance (监视) cameras- reaction to the new technology was mixed. Some said the camera was going too far and violating privacy,but others said they are willing to put safety before privacy concerns.' There ' s surveillance everywhere anyway,' said one commuter. 'I don' t think it' s much of a difference. I don' t care that they can see through me because they can see me anyway.' Some experts said the privacy violation of the camera was not worth the benefit. ' What we should consider is how much we want to lose our privacy in order to obtain a sort of national security,' said David Murakami Wood, director of the Surveillance Studies network,which deals with surveillance and privacy problems.' In most cases this isn' t real security-it 's a sense of safety that has very little real effect.' 1. What can we learn about T5000? A. It can detect metallic and nonmetallic objects underneath. B. It can see through clothing or walls by sending out T-rays. C. It was first used to observe stars by astronomers. D. It is widely used at airports around the world. 2. What is the most probable purpose of the new invention? A. To improve people ' s life standard. B. For scientific research. C. For commercial benefits. D. For safety reasons. 3. Which is most probably the opinion of people on using the new camera? A. Some agree to its use as it is new technology to protect privacy. B. Some agree to its use because safety is the most important. C. Some don' t agree to its use because it makes no difference. D.Some people don' t care because they know little about it. 4. What' s the main idea of the last paragraph? A. Safety is more important than privacy. B. T5000 is more beneficial than harmful. C. T5000 does not really provide security. D. It's not worth giving up privacy for safety.