牵牛子药用部位是（）
A.果皮
B.种子
C.种仁
D.果实
E.幼果
参考答案：B
—Have you made up your mind how to cheer up the sick kids?
—__ .
A．With dancing
B．By singing songs
C．To tell jokes
D．Given them toys
飞轮发出敲击声是什么原因？
