2024 年 12 月大学英语四级考试真题（第 1 套）

Scientists have known that depriving adult mice of vision can increase the sensitivity of individual neurons (神经元) in the part of the brain devoted to hearing. New research from biologists at the University of Maryland __26__ that sight deprivation also changes the way brain cells __27__ with one another, shifting the mice's sensitivity to different frequencies.

"This study __28__ what we are learning about how manipulating vision can have a __29__ effect on the ability of an animal to hear long after the window for auditory (听觉的) learning was thought to have __30__," said Patrick Kanold, senior author of the study.

It was once thought that the sensory regions of the brain were not __31__ after a critical period in childhood. This is why children learn languages much more __32__ than adults. Kanold's earlier research disproved this idea by showing that depriving adult mice of vision for a short period increased the sensitivity of individual neurons in the auditory cortex (皮质), which is devoted to hearing.

Young brains wire themselves according to the sounds they hear frequently, assigning areas of the auditory cortex to __33__ frequencies based on what they are used to hearing. The researchers found that, in adult mice, a week in the dark also changed the __34__ of space to different frequencies.

"We don't know why we are seeing these patterns," Kanold said. "We __35__ that it may have to do with what the mice are paying attention to while they are in the dark."

The weakening of the human connection to nature might be good for economic growth but is bad for people. A tipping point was reached in 2020 when human-made materials - such as steel, concrete and plastic - were found to weigh more than all life on Earth. Continuing to grow concrete forests rather than real ones is shortsighted. Simply being in the nearest wood has such health benefits that the Woodland Trust successfully lobbied for it to be prescribed by doctors. Yet slipping from popular culture is the wonder and beauty of the natural world. For every three nature-related words in hit songs of the 1950s, researchers found, there was only slightly more than one 50 years later. It is not a moment too soon that teenagers will be able to take a natural history test, given that for decades children have been able to name more video game characters than wildlife species. Part of remedying this social disease would be for parliament to pass a "right to grow" law, allowing anyone to turn underused public spaces into vegetable and fruit gardens. The idea is for people to get back in touch with the soil - while producing food sustainably. Vegetable planting has a respectable tradition. In April 1649, locals responded to high prices and food shortages by cultivating vegetables on common land in Southern England. The practice of throwing seed bombs to turn vacant plots of land green took off in 1970s New York, and has been revived by green-thumbed social media influencers who defy local US regulations in a war on ugly spots in cities.

Apart from the urgent task of providing more healthy nutrients to those who increasingly can't afford them, publicly accessible fruit and vegetable gardens connect what we eat to where it comes from - the means of production, if you will. They can make unlovely spaces lovely, and marry use and beauty as well as help promote a sense of community. Plants are also, of course, our first defence against species loss and climate change. Such planting is a small step for humanity - in the right direction.

Engineering in the U.S. has long been a male-dominated profession. Fifty years ago, it looked like that might change.

In 1970, the percentage of women majoring in engineering was less than 1%. In 1979, that number was 9%. Many hoped women would continue to enter the field at the same rate. But that's not what happened. Today, only 21% of engineering majors are women, a number largely unchanged since 2000.

I am a historian who, along with my colleagues, surveyed 251 women engineers who graduated from college in the 1970s. These pioneers reflected on the challenges they faced - and had advice for women entering the field today.

One survey taker explained, "The greatest challenge for me was continuing to believe in myself, when all the messages I was getting were that I would never be taken seriously or promoted or given raises at the same rate as men, who were clearly less qualified and not as smart as I was."

A chemical engineer who worked in manufacturing agreed, "You have to prove yourself just because you are female. And you have to work twice as hard!"

A civil engineer said, "We are 'women engineers.' People don't refer to a man as a 'man engineer' - he's an engineer. We are constantly reminded that we don't truly belong." Another civil engineer stated, "On many levels, you're never quite one of the group."

Women also talked about family caregiving responsibilities. A retired vice president from a major chemical company stated, "Young women engineers are on an equal footing until they have children, then they struggle to balance work and family - and compete with men who don't have the same household responsibilities."

But over the years things have changed a lot. Young women engineers are more accepted mostly because there are just more of them.

Many women engineers hailed the benefits of their chosen career. A program manager in manufacturing stated that engineering is the best degree. A mechanical engineer said, "It will give you the flexibility to do almost anything. It is also satisfying to see the effects of what you have done."