下列器官或组织能产生激素的有()

A.性腺

B.胃肠道

C.下丘脑

D.肾

E.腺垂体

0ne of the limitations of foam as an extinguishing agent is that foam（）.

A.cannot be made with salt water

B.is heavierthan oil and sinks below its surface

C.is corrosive and to fire fighters

D.conducts electricity