2016年12月英语六级真题答案（第3套）

Dr. Donald Sadoway at MIT started his own battery company with the hope of changing the world's energy future. It's a dramatic endorsement for a technology most people think about only when their smartphone goes dark. But Sadoway isn't alone in trumpeting energy storage as a missing link to a cleaner, more efficient, and more equitable energy future.

Scientists and engineers have long believed in the promise of batteries to change the world. Advanced batteries are moving out of specialized markets and creeping into the mainstream, signaling a tipping point for forward-looking technologies such as electric cars and rooftop solar panels.

The ubiquitous (无所不在的) battery has already come a long way, of course. For better or worse, batteries make possible our mobile-first lifestyles, our screen culture, our increasingly globalized world. Still, as impressive as all this is, it may be trivial compared with what comes next. Having already enabled a communications revolution, the battery is now poised to transform just about everything else.

The wireless age is expanding to include not just our phones, tablets, and laptops, but also our cars, homes, and even whole communities. In emerging economies, rural communities are bypassing the wires and wooden poles that spread power. Instead, some in Africa and Asia are seeing their first light-bulbs illuminated by the power of sunlight stored in batteries.

Today, energy storage is a $ 33 billion global industry that generates nearly 100 gigawatt-hours of electricity per year. By the end of the decade, it's expected to be worth over $ 50 billion and generate 160 gigawatt-hours, enough to attract the attention of major companies that might not otherwise be interested in a decidedly pedestrian technology. Even utility companies, which have long viewed batteries and alternative forms of energy as a threat, are learning to embrace the technologies as enabling rather than disrupting.

Today's battery breakthroughs come as the world looks to expand modern energy access to the billion or so people without it, while also cutting back on fuels that warm the planet. Those simultaneous challenges appear less overwhelming with increasingly better answers to a centuries-old question: how to make power portable.

To be sure, the battery still has a long way to go before the nightly recharge completely replaces the weekly trip to the gas station. A battery-powered world comes with its own risks, too. What happens to the centralized electric grid, which took decades and billions of dollars to build, as more and more people become "prosumers," who produce and consume their own energy onsite?

No one knows which — if any — battery technology will ultimately dominate, but one thing remains clear. The future of energy is in how we store it.

More than 100 years ago, American sociologist W. E. B. Du Bois was concerned that race was being used as a biological explanation for what he understood to be social and cultural differences between different populations of people. He spoke out against the idea of "white" and "black" as distinct groups, claiming that these distinctions ignored the scope of human diversity.

Science would favor Du Bois. Today, the mainstream belief among scientists is that race is a social construct without biological meaning. In an article published in the journal Science, four scholars say racial categories need to be phased out.

"Essentially, I could not agree more with the authors," said Svante Paabo, a biologist and director of the Max Planck Institute for Evolutionary Anthropology in Germany. In one example that demonstrated genetic differences were not fixed along racial lines, the full genomes (基因组) of James Watson and Craig Venter, two famous American scientists of European ancestry, were compared to that of a Korean scientist, Seong-Jin Kim. It turned out that Watson and Venter shared fewer variations in their genetic sequences than they each shared with Kim.

Michael Yudell, a professor of public health at Drexel University in Philadelphia, said that modern genetics research is operating in a paradox: on the one hand, race is understood to be a useful tool to illuminate human genetic diversity, but on the other hand, race is also understood to be a poorly defined marker of that diversity.

Assumptions about genetic differences between people of different races could be particularly dangerous in a medical setting. " If you make clinical predictions based on somebody's race, you're going to be wrong a good chunk of the time," Yudell told Live Science. In the paper, he and his colleagues used the example of cystic fibrosis, which is under diagnosed in people of African ancestry because it is thought of as a "white" disease.

So what other variables could be used if the racial concept is thrown out? Yudell said scientists need to get more specific with their language, perhaps using terms like "ancestry" or "population" that might more precisely reflect the relationship between humans and their genes, on both the individual and population level. The researchers also acknowledged that there are a few areas where race as a construct might still be useful in scientific research: as a political and social, but not biological, variable.

While we argue phasing out racial terminology (术语) in the biological sciences, we also acknowledge that using race as a political or social category to study racism, although filled with lots of challenges, remains necessary given our need to understand how structural inequities and discrimination produce health disparities (差异) between groups." Yudell said.