下列是脊椎动物的一组是( )
①水蛭 ②蛔虫 ③海马 ④涡虫 ⑤蚯蚓 ⑥蝾螈 ⑦避役 ⑧虾.
--- Do you know Amy came to school this morning?
--- Her bike was broken, so she had to walk.