对机体的生长发育起关键作用的激素是
A．生长素B．肾上腺糖皮质激素C．肾上腺素D．甲状腺激素E．甲状旁腺激素
参考答案：A
股骨粗隆间骨折能够使用的内固定是（）.
A.重建钉
B.空心钉
C.Richard钉
D.伽玛钉
E.骨圆钉
Deck foam systems，designed to protect cargo areas on tankers built after January 1，1975，must have a supply of foam-producing material to operate the system at its designed rate of foam production for（）.
A.15 minutes without recharging
B.20 minutes without recharging
C.25 minutes without recharging
D.30 minutes without recharging
