超声波从材料1进入材料2，随声阻抗比Z1/Z2的增大而透过的声压（）。A、减小 B、

平板闸阀的闸板结构特征为()

(A)弹性闸板;

(B)平行组合式闸板;

(C)楔式闸板上有一通孔;

(D)平行式闸板上有一个与管道内径等径的通孔

阅读理解。

     In the past, people who graduated from college felt proud of their academic (学业的) achievements and

confident that their degree would help them to find a good job. 　　

     However, in the past four years the job market has changed greatly. This year's college graduates are

facing one of the worst job markets. For example, Ryan Stewart, a graduate of San Jose State University,

got a degree in religious studies, but he has not gotten any job offers. He points out that many people already

working are getting laid off and don't have jobs, so it's even harder for new college graduates to find jobs. 　　

     Four years ago, the future looked bright for his class of 2006. There were many high-tech ("dot com")

job opportunities, graduates received many job offers, and they were able to get jobs with high salaries and

benefits such as health insurance and paid vacations. However,"Times have changed. It's a new market,"

according to an officer of the university. 　　

     The officer says students who do find jobs started preparing two years ago. They worked during summer

vacations, they have had several short-time jobs, and they majored in fields that are still paying well, such as

accounting or nursing. 　　

     Even teaching is not a secure profession now. Ryan Stewart wanted to be a teacher. But instead he will

probably go back to school in order to become a college teacher. He thinks college teaching could be a good

career even in a bad economy. 　　

     In conclusion, these days a college degree does not automatically lead to a good job with a high salary.

Some students can only hope that the value of their degree will increase in the future.

1. What did a college degree mean to people in the past? 　　

A. It was a proof of their professional skills.　　

B. It would guarantee their quick promotion (升职). 　　

C. It built up their confidence in the job market.　　

D. It would help them to start an academic career.

2. Why does Ryan Stewart want to be a college teacher? 　　

A. Teaching jobs are well-paid.　　

B. He majored in teaching in the university. 　　

C. College teaching is less challenging than high-tech jobs. 　　

D. College teaching career won't be influenced by economy.

3. It can be concluded from the passage that _____. 　

A. the value of a college degree has decreased now　

B. new college graduates today can't find any job 　

C. a college degree can still lead to a good job　　

D. graduates must prepare early to find jobs

不论设备的电源接口和线路接口是否在同一侧面板，线路接口必须朝（），方便维护。线路接口即业务接口，比如，交换机的以太口、协转的2M接口及以太口等。

A.机架左门

B.机架右门

C.机架前门

D.机架后门

当代人事行政发展的总体方向最主要的表现为（）。

A．集权主义

B．工具主义

C．人本主义

D．功利主义

罢工、停工或者劳动受到限制