题干

如图为真核细胞蛋白质合成过程中遗传信息流动图解,1,2,3表示相关过程,据图判断下列说法正确的是(    )

A:1过程主要发生于细胞核内,2过程主要发生于细胞质中

B:3过程以mRNA作为模板,核糖体在mRNA上的移动方向是从右到左

C:核苷酸序列不同的基因可表达出相同的蛋白质

D:翻译时,图中3过程mRNA每次能结合多个核糖体,产生的各肽链氨基酸序列不同

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C

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阅读理解

    As self — driving cars come closer to being common on American roads, much of the rhetoric (说辞) promoting them has to do with safety. About 40,000 people die on U. S. roads every year, and driver errors are linked to more than 90 percent of crashes. But many of the biggest advocates of autonomous vehicles aren't car companies looking to improve the safety of their existing products. Huge backing for self - driving technologies is coming from Silicon Valley giants like Google and Apple.

    Those of us who have studied the relationship between technology and society tend to look more carefully at the motivations behind any technological push. In this case, it's clear that in addition to addressing safety concerns, Silicon Valley firms have a strong incentive (动机) to create a new venue for increasing the use of their digital devices. Every minute people spend on their mobile phones provides data - and often money - to tech companies.

    At present, digital devices and driving are in conflict: There are serious, often fatal, consequences when drivers use smartphones to talk or to text. Regulators and safety advocates look to resolve dial conflict by banning phone use while driving - as has happened in virtually every state. But the tech companies are taking a different approach. The obvious answer for Silicon Valley is creating an antomobile in which continuous cellphone use no longer poses a threat to anyone.

    In recent years, the amount of time adults spend on their mobile devices has grown rapidly. At the moment, it's around four hours a day for the average adult in the U. S. However, that rapid growth is likely to slow down as people run out of time that ' s available for them to use their devices. Unless, of course, there's a new block of time that suddenly opens up. The average American now spends about 48 minutes in a car every day, a sizable opportunity for increased cellphone use.

    So as the public conversation around autonomous cars highlights the safety advantages, don't forget the tech industry ' s powerful desire for more profits, which goes well beyond simply saving us from ourselves.