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    Most people hope to have a memory which helps them succeed in study, work and life. Can memory be improved? Luckily, hundreds of studies in the past 50 years have already given us a definite answer.

    A healthy lifestyle keeps our brain young and memory sharp. First of all, it is necessary to have a healthy diet. Eating more food rich in B vitamins and vitamin E, such as vegetables and lean meat, helps you have a better memory. Doing exercise can keep your brain alive, too. Proper exercise provides much oxygen for the brain. Running, riding a bike, swimming and even walking two or three times a week are helpful. Moreover, getting enough sleep is important. Only when your brain gets a good rest, can it work well. The healthier your lifestyle is, the better your memory will become. But do not expect a sudden change－it takes a long time to make a difference.

    Memory stills help you remember things better. The following three are the most widely used. Chunking is a way of remembering a piece of information by cutting it into small ones. For example, to memorize a ten-digit telephone number 2127983630, you can divide the digits into three groups: first 212, then 798, and lastly 3630. This method is far more effective than remembering a string of 10 digits. Organization means organizing information into groups of the same kind. For example, trees, grass and flowers are plants; tigers, pandas, horses and cows are animals. Imagery is remembering newly learnt information by using your imagination and connecting it with something that you are familiar with.

    However, memory skills will hardly work if you don't understand the information. What's more, only a regular review can make the memory last long. That is why students are always advised to go over what they have learnt and then use it as regularly as possible.

    Human brains are like muscles that needs nutrients and exercise to become stronger. If you make a few lifestyle changes and try some memory skills, you can certainly improve your memory.

    On July 20, 1969, Neil Armstrong became the first person to walk on the moon. The space suit Armstrong wore on his lunar mission has come to symbolize courage and human achievement. In 1971, the Smithsonian's National Air and Space Museum(NASM), in Washington, D.C., acquired (获得) Armstrong's suit. It stood proudly on display for visitors to admire, until there were changes in the suit's appearance. "Over time, the suit started to show signs of deterioration," Lisa Young said. Young is an objects conservator (文物修复员) at NASM. It is her job to preserve(维护)historical and cultural objects.

    "Plastics are tricky to conserve," Young says. They tend to degrade (降解)over time. Neoprene is one type of plastic in Armstrong's suit. The material can turn brittle and break into tiny pieces. This would ruin the space suit. NASM, seeking ways to preserve this historical treasure, removed it from display in 2006.

    What causes plastic to degrade in the first place? "Many things," Odile Madden says. Madden is a scientist in California. She explains that sunlight, water, humidity, and dust can cause plastics to degrade. "Some plastics will break down no matter what we do," Madden says.

    Yet history can still be saved. Scientists have found that storing plastics in cooler temperatures, with lower humidity levels, can slow degradation. Young says Armstrong's suit is currently in storage at a temperature of 63°F and a lower relative humidity of 30%. These conditions will be maintained when Armstrong's suit returns to a museum display case in time for the 50^th anniversary of the moon landing.

    Plastic degradation affects art, too. Artist Claes Oldenburg created False Food Selection in 1966.It consists of plastic food displayed in a wooden box. The plastic food used to look real. Now, some of it has flattened and yellowed. Georgina Rayner is a conservation scientist at Harvard Art Museums, in Cambridge. She says the artwork's wooden box produces an acidic (酸的) gas that eats away at the plastic. This speeds up the degradation process. But Rayner is motivated to conserve this artwork and others like it. "Plastics are a part of our history," she says. "It's important to preserve them so that future generations can understand the journey we've taken."