is surprising to us is that Tom can speak English fluently as though he were a native speakdr.

A．What

B．That

C．Which

D．As

对于血液粘滞性的叙述，错误者为

A．与水相比，血液的粘滞性为4～5

B．全血的粘滞性主要决定于所含的红细胞数目

C．血浆的粘滞性主要决定于血浆蛋白质的含量

D．血流速度显著减慢时，血液粘滞性相对减小

E．血液粘滞性与血流阻力成正比