尿液标本作L型菌培养时，培养基中加入20%蔗糖的原因是

A．提供高营养
B．使尿中蛋白质变性
C．稀释尿液
D．保持高渗环境
E．中和尿液的酸度

Moving of an anchor over the sea bottom involuntarily because it is no longer preventing the movement of the vessel defines（）.

A.dredging ( of anchor )

B.dragging ( of anchor )

C.weighing anchor

D.walking out anchor