Renaissance is a French word. It means “rebirth”. It's a strange name for a period of history. What was exactly “ reborn” during the Renaissance?

    To answer this question, we need to look back at the time of the Roman Empire. At this time Roman artists, scientists and writers influenced by Greek ideas were the world's most advanced. They had become skilled observers of the natural world around them, and had become experts in studying animals, plants, the human body or the stars and planets. They wrote down their ideas about what they saw, and based their theories about the world on their observations.

    During the fourth and fifth centuries the Roman Empire slowly broke down. Many of the Romans' art and sculptures were destroyed and some manuscripts（原稿）were lost as well. But most importantly, some of the ancient attitudes were lost. A questioning approach to the world was replaced by an unquestioning one.

    Why did this happen? One reason was to do with the influence of the Christian Church. Through the thousand years following the fall of the Roman Empire, the Church controlled many aspects of life including education and learning. The Church ran all the universities and thought that the aim of a university should be to teach old ideas more clearly, not to introduce new ones. The scholars in the universities were expected to study God and heaven from the Bible and ancient books, rather than the world around them.

Take medicine for example. The main textbook for doctors had been written by a Greek doctor called Galen more than a thousand years earlier. But when Roger Bacon, a thirteenth-century priest（牧师）, said that a new approach to medicine was needed — doctors should do their own original research instead of reading writers from the past such as Galen-the Church put him in prison.

    By the time of the fourteenth century, however, some parts of the Christian Church were becoming less strict about their ideas and there was a new state of mind among artists, doctors and scientist. People wanted to find out more about the world by studying it. This attitude of investigation had been common in classical scholars, and it was ‘reborn' during the Renaissance.

阅读下列短文，从每题所给的四个选项 （A 、B 、C  和 D ）中，选出最佳选项。

    In an ideal world, people would not test medicines on animals. Such experiments are stressful and sometimes painful for animals, and expensive and time-consuming for people. Yet animal experimentation is still needed to help bridge vast gaps in medical knowledge. That is why there are some 50 to 100 million animals used in research around the world each year.

    Europe, on the whole, has the world's most restrictive (严格的) laws on animal experiments. Even so，its scientists use some 12 million animals a year, most of them mice and rats, for medical research. Official statistics show that just 1.1 million animals are used in research in America each year. But that is misleading. The American authorities do not think mice and rats are worth counting and, as these are the most common laboratory animals, the true figure is much higher. Japan and China have even less comprehensive (全面的) data than America.

    Now Europe is reforming the rules governing animal experiments by restricting the number of animals used in labs. Alternatives to animal testing，such as using human tissue or computer models, are now strongly recommended. In addition, sharing all research results freely should help to reduce the number of animals for scientific use. At present, scientists often share only the results of successful experiments. If their findings do not fit the hypothesis (假设) being tested, the work never sees the light of day. This practice means wasting time, money, and animals' lives in endlessly repeating the failed experiments.

    Animal experimentation has taught humanity a great deal and saved countless lives. It needs to continue，even if that means animals sometimes suffer. Europe's new measures should eventually both reduce the number of animals used in experiments and improve the way in which scientific research is conducted.

    All too often, a choice that seems sustainable(可持续的)turns out on closer examination to be problematic. Probably the best example is the rush to produce ethanol(乙醇) for fuel from corn. Corn is a renewable resource —you can harvest it and grow more, almost limitlessly. So replacing gas with corn ethanol seems like a great idea. 

    One might get a bit more energy out of the ethanol than that used to make it, which could still make ethanol more sustainable than gas generally, but that's not the end of the problem. Using corn to make ethanol means less corn is left to feed animals and people, which drives up the cost of food. That result leads to turning the fallow land –including, in some cases, rain forest in places such as Brazil—into farmland, which in turn gives off lots of carbon dioxide (CO) into the air. Finally, over many years, the energy benefit from burning ethanol would make up for the forest loss. But by then, climate change would have progressed so far that it might not help.

    You cannot really declare any practice “sustainable” until you have done a complete life-cycle analysis of its environmental(环境的) costs. Even then, technology and public keep developing, and that development can lead to unforeseen and undesired results. The admirable goal of living sustainably requires plenty of thought on an ongoing basis.

    Drug companies have spent billions of dollars searching for therapies to reverse or significantly slow Alzheimer's disease, but in vain. Some researchers argue that the best way to make progress is to create better animal models for research, and several teams are now developing mice that more closely imitate how the disease destroys people's brains.

    The US National Institutes of Health (NIH), the UK Dementia Research Institute and Jackson Laboratory (JAX) - one of the world's biggest suppliers of lab mice - are among the groups trying to genetically design more suitable mice. Scientists are also exploring the complex web of mutations(突变) that influences neurological (神经学的) decline in mice and people.

    "We appreciate that the models we had were insufficient. I think it's sort of at a critical moment right now." says Bruce Lamb, a neuro-scientist at Indiana University ~ho directs the NIH-funded programme.

    Alzheimer's is marked by cognitive impairment(认知损伤) and the build-up of amyloid-protein plaques (淀粉样蛋白块) in the brains of people, but the disease does not occur naturally in mice. Scientists get around this by studying mice that have been genetically modified to produce high levels of human amyloid protein. These mice develop plaques in their brains, but they still do not display the memory problems seen in people.

    Many experimental drugs that have successfully removed plaques from mouse brains have not lessened the symptoms of Alzheimer's disease in people. One focused stumble came last month, when three companies reported that their Alzheimer's drugs had failed in large, late-stage clinical trials. Although the drugs successfully blocked the accumulation of amyloid protein in mice, they seemed to worsen cognitive decline and brain shrinkage in people.

    The drive for better mouse models comes as genomics studies are linking the most common form of Alzheimer's to dozens of different genes. This diversity suggests that each case of the disease is caused by a different combination of genetic and environmental factors. "There is no single Alzheimer's disease," says Gareth Howell, a neuro-scientist at Jackson Laboratory (JAX) in Bar Harbor, Maine.

    Howell argues that scientists' reliance on lab mice with only a few genetically engineered mutations might have limited research. His own work suggests that in mice, just as in people, genetic diversity plays a part in determining how Alzheimer's develops.

Emilia Dobek traces her interest in space and the universe back to third grade when she and her father watched a blood moon—a total lunar eclipse (月蚀)—on the roof of their house.

    Now a seventh-grader at East Prairie Elementary School, Dobek recently won the national Discovery Education Lockheed-Martin Beyond Challenge by designing a space station for travelling to Mars.

    She says that night watching the lunar eclipse started a strong desire in her that has yet to run out of fuel. So when her teacher Andrea Smeeton received information about the national challenge, Smeeton said she immediately had one student in mind.

    "I knew she would love the challenge and that she would go way beyond in her search," Smeeton said. "She immediately started researching bone density (密度) of astronauts and how to have food on Mars."

    "My design will ensure the safety of the astronauts but also make sure their comfort is out of this world," Dobek says.

    Dobek's design calls for building the MSS or Mars Storage Station to put the supplies in. It also includes the SGF or Self-Crowing Farm, and she details how it would work with the elements on Mars.

    Then there is physical and leisure activity for the astronauts under Dobek's design. A simulation (模拟装置) allows astronauts to choose their exercise machine and virtual (虚拟的) reality environment. Rooms have circular ceilings so astronauts will be able to watch downloaded shows and even see places on Earth, such as their homes.

    "I want to tell other kids to follow their passions." Dobek said. "Whatever they want to do they should push for it and always try their best."

    I never saw my father home from work late or ill, nor did I ever see my father take a "night out with the boys". He had no hobbies but just took care of his family.

    For 22 years, since I left home for college, my father called me every Sunday at 9:00 am. He was always interested in my life—how my family was doing. The calls even came when he and my mother were in Australia, England or Florida.

    Nine years ago when I bought me first house, my father, 67 years old, spent eight hours a day for three days, painting my house. He would not allow me to pay someone to have it done. All he asked was a glass of iced tea, and that I hold a paintbrush for him and talk to him. But I was too busy, for I had a law practice to run, and I could not take the time to hold the paintbrush, or talk to my father.

    Five years ago, my 71-year-old father spent five hours putting together a swing set (秋千) for my daughter. Again, all he asked was that I get him a glass of iced tea, and talk to him. But again, I had laundry to do, and the house to clean.

    The morning on Sunday, January 16, 1995, my father telephoned me as usual, this time he had seemed to have forgotten some things we had discussed the week before. I had to get to church, and I cut the conversation short.

    The call came at 4:40 am. That day my father was sent to hospital in Florida. I got on a plane immediately, and I vowed (发誓) that when I arrived, I would make up for the lost time, and have a nice long talk with him and really get to know him.

    I arrived in Florida at 1:00 am, but my father had passed away at 9:12 pm. This time it was he who did not have time to talk, or time to wait for me.

    In the years since his death I have learnt much about my father, and even more about every single day.