四川省成都市高考英语阅读理解二轮基础训练 80 集连载（9）及（解析）答案高考训练题。阅读理解。阅读下列短文，从每题所给的四个选项（A、B、C 和 D）中，选出最佳选项。In science fiction TV programs such as Star Trek , tractor beams (光线) are used to draw spaceships and move objects For years, scientists have labored to reproduce this feat（技艺）. In . they succeeded A team of British and Czech scientists, led by Dr Tomas Cizmar. say they have created a rea-life "tractor beam". like the kind from Star Trek . which uses a line of light to attract objects. at least at a microscopic level Light control techniques have existed since the l970s. but this is thought to be the first time a beam has been used to draw objects towards a light source Usually when microscopic objects are hit by a line of light. they are forced along the direction of the beam After many years' research. Dr Cizmar's team discovered a technique that allows for the radiant force(辐射力) of light to be changed and to use the negative force to draw out certain particles（小颗粒） Dr Cizmar says that even though it is a few years away from practical use. the technology has huge potential for medical research In particular. the tractor beam is highly selective in the particles it can attract. so it can pick up particles that have specific characteristics. such as size or composition. in a mixture "Eventually, this could be used to separate white blood cells. for example," Dr Cizmar told BBC News It has been a primary plot design in science fiction TV programs and movies to allow objects like spaceships to be trapped in a line of light But Dr Cizmar said this particular technique would not eventually lead to that A transfer of energy ha...
