什么是音像档案？

阅读理解。

     Li Jun, a 17-year-old girl ① Shenzhen Foreign Language School, still can't believe her 10-day free training

camp in the Alps in Switzerland last month was true!

     But how did she achieve this once-in-a-lifetime opportunity?

     Last October, a piece of short world news in a newspaper "免费看世界②", caught her eye. When she

asked her friends if the story was real, they laughed at her, for they thought she was day-dreaming.③ However,

Li decided to apply online the following weekend.

     On December 14, Li Jun surprised her friends with an invitation letter from the program, the Pangaea Young

Explorer Selection Camp set up by South African explorer Mike Horn.

     Because of her performance during the training, Li was chosen as one of the eight young explorers to join

Mike Horn in the South Island of New Zealand in May.

1. 在①处的空白处填入适当的词，使句意完整。

    ___________________________________________________

2. 将②句泽为英文。 

    ___________________________________________________

3. 将③处画线的句子译为中文。

    ___________________________________________________

4-5 判断正(T)误(F)。

( )4. The free training camp lasts for ten days.

(     )5. AII the friends believed what the newspaper said.

在三轴压缩试验中，当试验无明显破坏值时，为了简单，可采用应变为15％时的主应力差作为破坏值

下图中甲、乙、丙反映了三类工厂的投入构成情况，读图，回答问题。

乙类工厂运费低的原因最不可能是（）

A.需要的原料和能源少

B.产品科技含量高

C.以航空运输为主

D.靠近原料地和消费市场

图5-1资本配置线和无差异曲线

曲线（）反映了投资者可获得的最大效用水平。

A．1

B．2

C．3

D．4

怎么防止焊接弯头“扭曲”和“勾头”现象？