《素问•阴阳应象大论》中“清阳出上窍”，“清阳”是指（）
A、糟粕
B、使上窍发挥各种功能的精微物质
C、饮食化生的精气
D、津液
E、营血
参考答案：B
关于混凝土立方体抗压强度评定办法，下列说法正确的是（）。
A.方差已知统计方法
B.方差未知统计方法
C.非统计方法
D.方差未知时，B和C任选一种
_____ in some rural schools that the teacher is even unable to walk through the rows of desks. [ ]
A. The classroom is as crowded
B. So crowded is the classroom
D. As crowded the classroom is
D. The classroom is such crowded
