旅客人身伤害按（）分为三种。A.种类 B.程度 C.性质 D.程序

临床化学实验室测定所用校准品大多为（）。

A.一级标准

B.二级标准

C.溯源性好的校正物

D.质控物

E.以上都不可

长15分米，宽7分米的纸片，最多能剪______个直径为2分米的圆片．

书鳃

Intact buoyancy is a term used to describe（）.

A.the volume of all intact spaces above the waterline

B.an intact space below the surface of a flooded area

C.an intact space which can be flooded without causing a ship to sink

D.the space at which all the vertical upward forces of buoyancy are considered to be concentrated