What would you like? [ ]
A. I'd like some beef.
B. Let me try.
C. Help yourself.
答案:A
以下哪一组特征是脊索动物与高等无脊椎动物共同具有?()
A、脊索、后口、真体腔
B、后口、三胚层、真体腔
C、咽鳃裂、两侧左右对称、真体腔
D、神经管、三胚层、两侧对称
男性,41岁,今晨跑步中突然右腰部阵发性剧痛,向下腹部放射,实验室检查见镜下血尿。应考虑是
A.肾肿瘤B.肾结石C.胆绞痛D.阑尾炎E.肠扭转