题干

下列说法正确的是(  )


A:离子反应的反应速率很慢,受温度影响很大,需要用活化能来引发

B:醋酸的腐蚀性比盐酸小,常用于卫生洁具的清洁或去除水垢

C:纯水和干木头都不导电,但木头用水浸湿后却可以导电

D:广泛pH试纸可以判别0.2或0.3的pH差值

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答案(点此获取答案解析)

C

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阅读理解

    What would the world be like if cars could drive themselves? Imagine seeing an empty car passing by on its way to pick up its owner, or a car full of passengers who are reading, listening to music or even sleeping, but none of them are worried about the road ahead.

Well, all of this could be the future of driving. There are several companies, including Google, working on driverless (无人驾驶的) cars, which are currently in the testing stages. If the tests are successful, these electric, self-driven cars could be available very soon. But, how is it possible for a car to drive itself?

    Cars already have many features allowing them to take over for drivers in certain situations. Some features include cars being able to park themselves, or slow down when they detect objects (物体) close by. They can also control the speed if there are dangerous conditions, such as snow or slippery (滑的) roads.

    Other features have also changed the way drivers react to some situations. Scientists and engineers believe, with the help of wireless signals, cameras and GPS, we are now at a stage where creatinga safe self-driving car might be possible.

    The self-driven car may be the answer to lowering the number of deadly (致命的) accidents caused by careless drivers or dangerous conditions. However, there are still some people who do not like the idea. American lawyer Whit Drake, for example, doesn't believe these cars are safe. He thinks the possibility of the technology making a mistake will be too high.