A、Because it can treat emotional problems and stone kinds of cancer. B、Because it can make stores brighter. C、Because it can mak

Now medical researchers say the wonderful feeling that comes with spring is not just in the artists’ minds. The researchers say it is a real change in body chemistry that takes place as our bodies react to the longer days. They say we arc sensitive to the brightness, the color and the amount of light we see.
    Too much sunlight, of course, can be dangerous. It can cause bums and skin cancer and can damage the eyes. But studies have shown that we need controlled amounts of sunlight or in- tense electric light all year long. In fact, light is being used effectively to treat emotional problems, skin diseases and even some kinds of cancer.
    Many people overcome the effects of less sunlight in winter. They move toward sunlight as if it were a manager. They choose to work at a desk near a window. They like to sit in sunny rooms. They turn on as many electric lights as they can. They shop in brightly lighted stores and stay away from dark ones. Sometimes they travel to warm, sunny places in winter.