血浆中水分占血浆量的（）
A.6.5%～8.5%
B.90%～91%
C.7%～8%
D.50%～70%
E.40%～50%
参考答案：B
China is a _____ country, but America is a _____ country. [ ]
A. developing; developing
B. developed; developed
C. developing; developed
D. developed; developing
示范的方向要注意示范面，示范面有正面示范、（）、（）和（）四种。
