“嫦娥一号”卫星接收地面指挥中心的运行指令进行变轨而奔向月球是通过一种波来实现的

On 1 January 2004, the value of an investor’s portfolio is $ 89000. The investor plans to donate $ 4000 to charity organization and pay $ 2000 to his insurance account on 31 December of 2004, but meanwhile he does not want the year-end portfolio value to be below $ 89000. If the expected return on the existing portfolio is 12 percent with a variance of 125, the safety-first ratio that would be used to evaluate the portfolio based on Roy’ s criterion is closest to:（）

A. 0.236.

B. 0.365.

C. 0.471.

古人云“三思而后行”，这其中包含的含义是

A．行为前预见与选择

B．行为后不要承担责任

C．行为中要自律与自控

D．行为后要自省与负责

按船舶经营方式不同，海洋运输可分为______

A．直运

B．转运

C．班轮运输

D．租船运输

E．分批运输

伸直型肱骨髁上骨折近折端移位方向是

A．向前下移位

B．向后下移位

C．向后移位

D．向前移位

什么叫基准？基准有哪几种？