问题 多项选择题

关于最优证券组合的选择,下列说法正确的是( )。

A.最优证券组合是无差异曲线簇与有效边界的切点所表示的组合

B.特定投资者可以在有效组合中选择他自己最满意的组合,这种选择依赖于他的偏好,投资者的偏好通过他的无差异曲线来反映

C.根据不同投资者的无差异曲线簇可获得各自的最佳证券组合

D.一个只关心风险的投资者将选取最小方差组合作为最佳组合

答案

参考答案:A,B,C,D

解析: 题中四项均是最优组合选择的因素。故选ABCD。

选择题
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阅读理解

     In the year 480 BC the Greek allies (联军) faced invasion by the King of Persia,Xerxes,who

commanded a huge army of about half a million men.When the Persian army marched into northern

Greece,the Greek states,led by Athens and Sparta,were ill equipped to deal with the threat.The Persians

were well supplied with food and weapons.Their army included infantry,cavalry,and a large navy.It seemed that they would easily defeat the Greeks.

     The Greek allies decided to send 10,000 men northwards to slow down the Persians,while the rest

prepared to defend their homelands.A group of 300 best Spartan soldiers were chosen to lead the force

going north,with Leonidas in command.Leonidas realised that the only hope of slowing the Persians would be to block the narrow passage of land at Thermopylae.The Pass of Thermopylae was the route between

the mountains and the sea,and was so narrow that only a few men could get through at a time.

     When the Persian army arrived at Thermopylae,they found Leonidas' tiny army opposing them.The

Persians attacked,but could not get through.They attacked again and again,but each time they were driven back by the Greeks,led by the fearless Spartans.Leonidas'plan worked well until a Greek traitor called

Ephialtes went to Xerxes.He told the Persian king about a goat's path in the mountains that would take the Persian army past Thermopylae.When Leonidas saw the enemy crossing the mountains,he realised that he could no longer hold Thermopylae.He sent all the Greek soldiers except the 300 Spartans back to their

homelands.

     The Spartans waited for the 500,000 Persians at the goat's path.Although hopelessly outnumbered,the Spartans fought bravely.They all died,but the other Greeks were able to get home to strengthen the

defences.

1. Compared with the Persian army,the Greek allies were very______.

A. powerful  

B. wise  

C. weak    

D. foolish

2. The Pass of Thermopylae was very important for the Greeks because________.

A. it was easy to hold but hard to attack

B. only very small boats could get through it

C. it was a secret pass unknown to the Persians

D. a huge number of soldiers could be stationed there

3. Why did Leonidas send most of his soldiers back to their homelands?

A. Because their homelands were under attack.

B. Because he found they were not brave enough.

C. Because the Persians gave up attacking Thermopylae.

D. Because he found it impossible to hold Thermopylae.

4. Which of the following is NOT true according to the passage?

A. Leonidas was a great commander.

B. The Persians failed to pass Thermopylae.

C. Ephialtes betrayed his own country.

D. The 300 Spartans would be regarded as heroes by the Greeks.

5. Which of the following would be the best title for the passage?

A. The Greek Allies  

B. The Goat's Path

C. The King of Persia  

D. Xerxes and Ephialtes