In the northeast of China, a dense forest grows in the low mountains, (know) as the Xiaoxing'an Mountains. People call it the hometown of the red pine tree. Its pine nuts are edible and can (use) to make oil. Its wood is light, soft, and delicate. However, its economic value is far less its ecological value. Wild (animal) such as black bears and squirrels like to store (they) pine nuts in different places as they prepare the winter. But they have poor memory and often forgot they have put these nuts. Those forgotten pine nuts sprout (发芽) in spring, (help) the red pine trees expand their territory. In addition to the red pine trees, there (be) many different kinds of trees in the Xiaoxing'an Mountains. Every autumn, these trees display the (beauty) colors of nature.
