问题 选择题

生物圈中具有多种多样的生态系统,下列生态系统属于人工生态系统的是(  )

A.森林生态系统

B.海洋生态系统

C.农田生态系统

D.草原生态系统

答案

人工的生态系统是由人类所建立的生态系统,即以人类活动为生态环境中心,按照人类的理想要求建立的生态系统.如农田生态系统,农田生态系统以农作物为主体,动植物种类相对较少.同野生植物相比,农作物抵抗旱、涝、病虫害的能力较差.因此,需要在栽培和管理中投入大量的人力和物力.所以,在此生态系统中,人的作用非常关键,一旦人的作用消失,农田生态系统就会很快退化,占优势地位的作物被杂草和其他植物所代替.

    自然生态系统是在一定时间和空间范围内,依靠自然调节能力维持的相对稳定的生态系统.如草原生态系统、河流生态系统、湿地生态系统等.由于人类的强大作用,绝对未受人类干扰的自然生态系统已经没有了.可见C符合题意.

故选:C

阅读理解

HK's Family Affair

      The 39th Hong Kong Art Festival, to be held early next year, will be based on the topic of "family"

The art festival, considered to be Asia's best, began in 1973.

     "We hope that people from Beijing and from all over the world will go to Hong Kong to enjoy the

different performances in our art festival,"Douglas Gautier, the festival's management director, said in a

press conference(发布会) in the capital.

     In the 29 days of the festival, which runs from March 8 to April 7,2012, the audience can choose from 111 performances of 51 programmes given by 700 foreign performers, 450 local artists and 160 actors

from the mainland.

      Programmes vary from classical music, jazz, world music, Western and Peking opera, drama and

dance to outdoor shows.

     The programmes include Beethoven's only opera Fidelio, Shakespeare's drama Romeo and Juliet, the

ballet Mozartina and African dances, to name just a few.

     The lineup(阵容)includes the English Touring Theatre, Prague Chamber Orchestra, Zurich Ballet, The Spanish National Dance Troupe, as well as Europe Galante the Petersen Quartet, pianists Angela Hewitt

and Lang Lang, and saxophonist Jan Garbarek.

      In order to increase attendance, hotels and airlines are offering discount packages along with art

festival ticket sales, most of which are at 20% and 30% cheaper.

      For more information, please check:

1. The press conference was held      ____.

A. in Hong Kong

B. in Europe

C. in Beijing

D. in England

2. By means of "discount packages", you can pay       ___ .

A. nothing for the cost

B. less than the usual cost

C. for the air ticket but not for the festival ticket

D. for the festival ticket but not for hotel rooms

3. According to the text, we do NOT have any information about      ____ .

A. who will perform on stage

B. what programmes there will be

C. when the 39th Art Festival will be held

D. which theatres will put on performances

4. The main purpose in writing this text is       ___.

A. to make the 39th Art Festival known

B. to announce the plan of the art festival

C. to introduce the cost of the art festival

D. to sell a service during the art festival

问答题 简答题