题目

According to the US government, wind farms off the Pacific coast could produce 900 gigawatts of electricity every year. Unfortunately, the water there is far too deep for even the tallest windmills (see picture) to touch bottom. An experiment under way off the coast of Norway, however, could help put them anywhere.The project, called Hywind, is the world’s first large-scale deepwater wind turbine (涡轮发电机). Although it uses a fairly standard 152-ton, 2. 3-megawatt turbine, Hywind represents totally new technology. The turbine will be fixed 213 feet above the water on a floati地轴与地球公转轨道面之间的夹角并不是固定不变的，严格地说，它一直有着微小的变化。若地轴与地球公转轨道面之间的夹角如下图所示，回答下列各题。1.若赤道面与地球公转轨道面之间的夹角如图所示，则夏至日地球上A. 极昼和极夜的范围会扩大 B. 温带范围会扩大C. 热带范围保持不变 D. 寒带范围缩小2.若地球公转轨道面与赤道面的夹角为0°，下列地理现象不会消失的是A. 四季更替 B. 回归年C. 极昼极夜 D. 太阳日