He can hardly swim, _______? [ ]
A. couldn't he?
B. can't he
C. could he
D. can he
答案:D
探索神经纤维动作电位形成的离子机制,属于哪类研究
A.整体水平B.局部水平C.组织水平D.细胞、分子水平E.器官、系统水平
上颌后堤区的宽度()
A.1~5mm
B.2~7mm
C.2~10mm
D.2~12mm
E.以上都不对