三角片形端生牙
A．鱼纲 B．两栖纲 C．爬行纲 D．鸟纲 E．哺乳纲
参考答案：A
下列哪项解剖结构不属于锥体外系统（）
A.纹状体
B.黑质
C.内囊
D.红核
E.丘脑底核
Our school is having a sports meeting. Someone ______ here already.
A. arrived B. have arrived C. has arrived
