A、Small. B、Changing. C、Remote. D、Unbearable. A原文提到，由于居住空间紧张，大多数人住在宿舍式房间里。tight living spaces表明居住空间比较拥挤，故A为答案。原文提到较远的营地使用分开的帐篷，所以

The Chinese Antarctica expedition returned to Shanghai on March 20 following a month living on the ice. It was the first time Chinese scientists had visited the Amery Ice Shelf—the longest ice shelf in the world. The team collected ice samples and data on temperatures, which are necessary for research on global warming. So far, about 27 countries have visited Antarctica for scientific research. Although the living conditions are very hard, many scientists have to stay there for long periods of time. So, how do they manage their lives on the ice?
    During the summer, the temperature in Antarctica reaches about -20℃. It falls to about -60℃ in winter. So, even if there are 24 hours of sunshine, scientists must keep wearing all the correct clothes to protect them from the cold. These clothes include jeans, running shoes, jackets, long underwear, boots and woolen socks. Although highly technical clothing provides much protection against the extreme cold, scientists often need to go outside when there is an icy wind blowing and the temperature is -30℃. Natural protection such as facial hair can also help. "That’s why many researchers wear a beard. It really does keep you warm," says German explorer Arved Fuchs. Usually, the polar researchers have good meals. Some even have feasts on holidays like Christmas and New Year’s Day. Vegetables are always welcomed and usually finished the quickest. Life on the ice means living with other researchers in tight living spaces. Most people sleep in dorm-style rooms. More remote field camps use separate tents. So, at least some researchers don’t have to put up with annoying snorers.
    13. Why did researchers visit Amery Ice Shelf?
    14. What is the matter that researchers care most for living in Antarctica?
    15. What best describes the living space of most researchers on the Amery Ice Shelf?