Bicycle lights may not exactly be a problem that needs solving, but the following can be said about most of them ---- they’re easily stolen if left on an unattended bike. People riding at dusk can forget to turn them on, and those same people can forget to turn them off when they reach their destination. Well, the makers of the Blink/ Steady Bike Light have set out to address all of those shortings.
The waterproof(防水的) Blink/ Steady is so far only available as a tail light, although a head light is on the way. It’s fixed onto the bike’s seat post. A built- in photosensor(感光器) tells when it’s bee dark enough for the light to be required, and allows it to e on once you begin the riding. According to the producers, it isn’t fooled by things such as headlights or streetlights. The light also contains an accelerometer, also known as a motion sensor, which can tell when the bike is in motion.
Between the two sensors, this means the light will e on only once it’s dark enough, and the bike is moving. Even when stopped at red lights, the small movements of the rider will reportedly be enough to keep the light activated---- it’ll go out after 30 seconds of plete inactivity. While this does mean that the two sensors are continuously powered up, they go into a very low---- power sleep pattern when the bike is sitting, unused.
Light is provided by two5- watt LEDs, seeable over a range of 180 degrees. And power es from two AAA batteries, which provided up to 200 hours of continuous run time. The designers and engineers behind the Blink/ Steady are now raising money for its mercial production. About US $95 will get you one if they bee available.
【小题1】The first paragraph is mainly to mean that .A．bicycle lights are worth a researchB．bicycle lights are not a problem at allC．bicycle lights are easy to deal withD．bicycle lights are difficult to turn off【小题2】According to the text, the Blink/Steady Bike Light is sensitive to .A．the weatherB．streetlightsC．headlightsD．natural light【小题3】Why is there an accelerometer in the Blink/ Steady Bike Light?A．To protect the bike against water.B．To tell if the bike is moving.C．To make the bike easy to ride.D．To judge the speed of the bike.【小题4】What can be inferred about the Blink/ Steady Bike Light?A．It will be turned off immediately if the bike stops.B．The traffic lights have no effect on the light.C．It won’t use any power if the bike is unused.D．It must meet two requirements if it es on.A
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(答案→)A
解析：文章关注自行车车灯的问题。自行车车灯虽不像汽车车灯那样，是一个小问题，但也值得研究。文章介绍了一种自行车车灯的工作原理。
【小题1】根据第一段第一行“Bicycle lights may not exactly be a problem that needs solving, but the following can be said about most of them”可知，自行车车灯虽然不是一个太大的问题，但也值得研究。故选A。
【小题2】根据第二段“when it’s bee dark enough for the light to be required”和“it isn’t fooled by things such as headlights or streetlights”可知，这种车灯会自己判断黑暗的程度来确定是否需要打开车灯，不会受到汽车前灯和路灯的影响。故选D。
【小题3】根据第二段最后一句“The light also contains an accelerometer, also known as a motion sensor, which can tell when the bike is in motion.”可知，accelerometer是用来判断自行车是否在行驶。故选B。
【小题4】根据第三段“Between the two sensors, this means the light will e on only once it’s dark enough, and the bike is moving.”可知，只有天足够黑，自行车在运转的时候，车灯才会亮。故选D。