题目

Summer brings flowers and dirt and barbeque smoke. In the most wintery places, there isn’t much outside on cold days except snow, strong wind and cars warming up. Pine needles(松针), wood smoke and snow—these are the smells of winter, and for people who live with different seasons, wintery weather brings its own set of olfactory(嗅觉的) experiences. But why does the cold of winter smell different from the heat of summer?One reason is that odor molecules(气味分子) move much more slowly as the air temperature drops, said Pamela Dalton, an olfactory scientist at the Monell Chemical S20．香港与祖国内地的经济互补性很强，其中香港具有的优势条件是（　　）?A．廉价的劳动力B．丰富的自然资源C．雄厚的工农业基础D．先进的技术和管理经验