问题 多项选择题

下列关于统计量的表述中,正确的有()。

A.统计量是样本的函数

B.估计同一总体参数可以用多个不同统计量

C.统计量是随机变量

D.统计量不能含有任何总体参数

E.统计量能含有未知的参数

答案

参考答案:A, B, C

解析:在样本抽取出来以后,样本值就是已经观察到的值,这个样本的统计量就是已知的,构成统计量的函数中不能包含未知因素。

单项选择题
阅读理解

阅读表达。

     Some countries have a large number of earthquakes. Japan is one of them, while others do not have many,

for example, there are few in Britain.

     There is often a great noise during an earthquake. The ground vibrates. Houses fall down. Railways are

broken, which causes trains to run off. Sometimes thousands of people are killed in different ways. About

60,000 were killed in 1783 in the south of Italy. Some people say that earthquakes often happen near volcanoes

(火山), but this is not true. The centres of some earthquakes are under the sea. The bottom of the sea suddenly

moves. The powerful forces inside the earth break the rocks. The coast is shaken and great waves appear.

These waves travel long distances and rush over the land when they reach it, breaking down houses and other

buildings. Sometimes they break more buildings than ____.

     A terrible earthquake happened in Assam, India, in 1986. The land near Shillong suddenly moved l.5 feet to

one side, and then back again. It continued to act like this 20 times a minute. Few buildings could stand what

was happening and great stones flew four feet high into the air. What kind of buildings stays up best in an

earthquake? The Americans studied carefully the results of the earthquake at San Francisco (1906) and believed

it best for buildings to be made with concrete (水泥) walls together by steel frame. Such are the buildings that

can't burn or fall easily.

1. What is the best title of the passage? (Please answer within lo words.)

    _____________________________________________________________________________________

2. Which sentence in the passage can be replaced by the following one? These buildings are very strong and

    do not burn easily. 

    _____________________________________________________________________________________

3. Please fill in the blank in the passage with proper words or phrases. (Please answer within 10 words.)

    _____________________________________________________________________________________

4. What do you think may happen before an earthquake? (Please answer within 30 words.) 

    _____________________________________________________________________________________

5. Translate the underlined sentence in the last paragraph into Chinese. 

    _____________________________________________________________________________________