问题 解答题

道路交通安全法中将饮酒后违法驾驶机动车的行为分成两个档次:“酒后驾车”和“醉酒驾车”,其检测标准是驾驶人员血液中的酒精含量Q(简称血酒含量,单位是毫克/100毫升),当20≤Q<80时,为酒后驾车;当Q≥80时,为醉酒驾车. 某市公安局交通管理部门在某路段的一次拦查行动中,依法检查了200辆机动车驾驶员的血酒含量,其中查处酒后驾车的有6人,查处醉酒驾车的有2人,依据上述材料回答下列问题:

(Ⅰ)分别写出违法驾车发生的频率和醉酒驾车占违法驾车总数的百分数;

(Ⅱ)从违法驾车的8人中抽取2人,求取到醉酒驾车人数的分布列和期望,并指出所求期望的实际意义;

(Ⅲ)饮酒后违法驾驶机动车极易发生交通事故,假设酒后驾车和醉酒驾车发生交通事故的概率分别是0.1和0.25,且每位驾驶员是否发生交通事故是相互独立的。依此计算被查处的8名驾驶员中至少有一人发生交通事故的概率。(精确到0.01)并针对你的计算结果对驾驶员发出一句话的倡议.

答案

(Ⅰ)  ; 25% 

(Ⅱ)

012
P
 

,实际意义:在抽取的两人中平均含有0.5个醉酒驾车人员.

(Ⅲ)

 (Ⅰ) ; 25%                                           (2分)

(Ⅱ) 解:设取到醉酒驾车的人数为随机变量,则可能取到的值有0,1,2

 ,.

012
P
则分布列如下

,实际意义:在抽取的两人中平均含有0.5个醉酒驾车人员.         (8分)

(Ⅲ)                                      (10分)

一句话倡议:答案开放,教师酌情给分                                 (12分)

选择题
单项选择题

阅读理解:请根据短文内容,为每题确定l个最佳选项。

The National Trust。

The National Trust in Britain plays an increasingly important part in the preservation for public enjoyment of the best that is left unspoiled of the British countryside. Although the Trust has received practical and moral support from the Government, it is not a rich government department. It is a voluntary association of people who care for the unspoiled countryside and historic buildings of Britain. It is a charity which depends for its existence on voluntary support from members of the public. Its primary duty is to protect places of great natural beauty and places of historical interest.

The attention of the public was the first drawn to the dangers threatening the great old houses and the castles of Britain by the death of the Lord Lothian, who left his great seventeenth-century house to the Trust together with the 4500-acre park and estate surrounding it. This gift attracted wide publicity and started the Trust’s “Country House Scheme” Under this scheme, with the help of the Government and the general public, the Trust has been able to save and make accessible to the public about 150 of these oil houses. Lats year, about 1.75 million people paid to visit these historic houses, usually at a very small charge.

In addition to country houses and open spaces, the Trust now owns some examples of ancient wind and water mills, nature reserves, 540 farms and nearly 2500 cottages or small village houses, as well as some complete villages. In these villages no one is allowed to build, develop or disturb the old village environment in any way and all the houses are maintained in their original 16th century style. Over 4,000 acres of coastline , woodland, and hill country are protected by the Trust and no development or disturbances of any kind are permitted. The public has free access to these areas and is only asked to respect the peace, beauty and wildlife.

Over the past 80 years the Trust has become a big and important organization and an essential and respected part of national life. It helps to preserve all that and of historical significance not only for future generations of Britons but also for the millions of tourists who each year invade Britain in search of a great historic and cultural heritage.

The word “invade” in Paragraph 4 is closet in meaning to______.

A.Come in without permission.

B.Enter with invitation.

C.Visit in large numbers.

D.Appear all of a sudden.