密集的小鸟虽被亮光惊醒，却仍纹丝不动，只有几只站在“天桥”上的母鸟偏着脑袋，警惕地瞧着我们。
O O O B-Thing I-Thing O O B-Thing I-Thing O O O O O O O O O O O O B-Metric I-Metric O O B-Location I-Location I-Location I-Location O O B-Thing I-Thing O O O O O O O O O O B-Person I-Person O