题目选项分析

Unlike historical evidence of weather patterns in other regions of the world, which scientists find abundantly represented in tree rings, ancient glacial ice, or layers of sediment from seasonal plankton, clues to the past climates of the North Pole are almost nonexistent

Unlike historical evidence of weather patterns in other regions of the world, which scientists find abundantly represented in tree rings, ancient glacial ice, or layers of sediment from seasonal plankton, there are few clues about past climates for the North Pole