For instance, it appears the ancestor of brainless starfish and sea urchins had a brain.例如, 无脑海星和海胆的祖先似乎曾有大脑.Brainy students box , will always pick their teachers'brains, but the brainless ones never do that.聪明敏锐的学生...

v.使乘火车( entrain的过去式和过去分词 )，拖，产生...

brainstormed的音标：...