GRE Reading Comprehension: Maggoosh-GRE阅读Maggoosh - 6HP47NFS522EWEEON

The Canadian elk has traditionally been limited in its geographic range by the presence of elderberries, its primary source of food, which only grow up until a certain point in the tundra. A recent rise in temperatures, however, has seen a spread in the growth of elderberries northwards into the tundra. Therefore, the overall range of the Canadian elk can be expected to increase.