飞机的抬轮速度VR应当是：（）.A.大于失速速度，小于VMCA B.仅需大于失速速度

在炉内800℃区域是（）。

A．直接还原

B．间接还原

C．直接还原与间接还原

妊娠期促进 * * 发育的激素有

A．雌激素

B．孕激素

C．垂体催乳激素

D．胎盘生乳素

E．HCG

断路器连接水平传动杆时，轴销应（）。

A.垂直插入

B.任意插入

C.水平插入

D.不插入

简述宫颈癌的治疗原则。

A certain Social Security recipient will receive an annual benefit of $12,000 provided he has annual earnings of $9,360 or less, but the benefit will be reduced by $1 for every $3 of annual earnings over $9,360. What amount of total annual earnings would result in a 50 percent reduction in the recipient’s annual Social Security benefit ？（）(Assume Social Security benefits are not counted as part of annual earnings.)

A．$15,360

B．$17,360

C．$18,000

D．$21,360

E．$27,360