题目

. LONDON(Reuters)—Ecotourism(生态旅游) is causing a lot of damage to wildlife and may be endangering the survival of the very animals people are flocking to see, according to researchers. Biologists and conservationists(自然环境保护论者) are worried because polar bears, dolphins, penguins and other creatures are getting stressed and losing weight and some are dying. “Evidence is growing that many animals do not react well to tourists in their backyard,” New Scientist magazine said. The immediate effects researchers have noticed are changes in behavior, heart rates, or stress 下列物体的棱长之和相等，体积最大的是（　　）A．B．C．D．