车窗外不时闪过一片片的红叶树林，颜老师向我们介绍，这就是当地有名的乌桕树。
B-Location I-Location I-Location O O O O O O O O B-Location I-Location I-Location I-Location O B-Person I-Person I-Person O B-Person I-Person O O O O O O O O O O O B-Thing I-Thing I-Thing O