______in health,he insisted on doing the experiment.

A．As he was poor

B．Poor as he was

C．Poor was he

D．Poor he was though

全口义齿修复与固位有关的因素，下列哪一项是错误的（）。

A．牙槽骨致密程度

B．口腔黏膜的性质

C．颌骨的解剖形态

D．颊侧墓托的伸展

E．前伸平衡