中心静脉压的正常值是()。
A.5~20cmH2O
B.10~20cmH2O
C.5~10cmH2O
D.15~20cmH2O
E.5~15cmH2O
参考答案:C
The conference ________ a full week by the time it ends. [ ]
A. must have lasted
B. would have lasted
C. will have lasted
D. has lasted
民用建筑中常用的平面组合形式有哪几种?它们各自的特点和适用范围是什么?