2024届高三英语二轮复习外刊阅读热点话题培优练5：科技发明

外刊阅读热点话题 培优练5科技发明 1.解 A Someday,you may no longer need to brush your teeth by hand.Instead, a group of billions of nanoparticles(could automatically do all that work for you.It would be especially life-changing for people who find it difficult or impossible to hold and move a toothbrush. Steager,an engineer at the University of Pennsylvania (Penn)in Philadelphia and Hyun Koo,an inventor and dental researcher there, found a way to form the nanoparticles into long,skinny bristles (a lot like the ones on a toothbrush.But these bristles shape-shift to fit whatever surface they encounter. The tooth-cleaning robot works thanks to two magnets(One goes each side of the teeth.The nanoparticles sit in a liquid between the magnets.When the magnets are turned off,the nanoparticles move randomly in the liquid.As soon as one magnet gets turned on,the nanoparticles gather together near its center.When the researchers turn on the other magnet and turn off the first one,the nanoparticles extend outward in long,skinny bristles.When there's a tooth in the way, these bristles can't stretch out as far as they want.So they push against the tooth's surface.If there's a gap between teeth,they push into the gap.Moving the magnets makes the bristles move against and between teeth.All that motion cleans the teeth.As a bonus,the nanoparticles also have strong power to kill viruses. The new device is just a proof of concept.The researchers still need to turn it into a product that people will want to use."There's a lot of engineering to get from here to there,but every good idea needs to have a start,"said Steager. 1.What is special about the tooth cleaner? A.It's water-proof. B.It's transformable C.It looks like a toothbrush. D.It contains skinny bristles. 2.What is Paragraph 3 mainly about? A.The working principle. B.The magnets'motion. C.The virus-killing process. D.The bristles'formation. 3.How does Steager feel about the future of the device? A.Uncertain. B.Confident. C.Concerned. D.Surpr