世界银行关于不可预见准备金的表述，正确的是（）。A．支付估算时不可能明确的潜在项目费

阅读短文，回答问题：

    双金属片是利用金属的热胀冷缩性质制成的一种自动开关，它的内外两层是由两种热膨胀性能不同的金属构成的．当温度变化时，双金属片的自由端会与旁边的静触片发生接触或分离，因此，利用双金属片可以实现对电路的自动温控． 学校科技小组参加社会实践活动，发现农村家庭在对家禽的孵化过程中，温度的控制不好掌握，因此，他们决定利用双金属片来实现自动温度控制．他们使用的双金属片在升高相同的温度时，内层热膨胀程度大，外层热膨胀程度小，当低于或者达到设定温度时，始终闭合，高于设定温度时，自动断开．（如图1）小虎设计的电路如图2所示，其中用到了两个完全相同的电热丝R₁、R₂，它们都能单独接入电路中工作。

（1）在该电路中双金属片起到               的作用。

（2）小明觉得这个电路只能以单一功率工作，不能在环境温度变化时达到孵化要求的温度，小明在原有电路上增加了一个开关S₂，使该孵化器能够以两种功率工作．根据你的理解，把图3所示的实物电路连接完整，达到两种功率工作的目的．改装前后电热丝的发热功率之比为                 。

（3）小华提出：我在小虎设计的电路上加装两个开关，就可以使该孵化器能够以三种功率工作。请你在图4中替小华画出设计电路图。

             图1                                                         图2                                        图3                                             图4

政务元数据分为（）、元数据实体和元数据元素三层。

下列的血气结果哪一个符合Ⅱ型呼吸衰竭（）

A.PaO₂<50mmHg，PaCO₂>45mmHg

B.PaO₂<50mmHg，PaCO₂>60mmHg

C.PaO₂<60mmHg，PaCO₂>50mmHg

D.PaO₂<40mmHg，PaCO₂>40mmHg

E.PaO₂<70mmHg，PaCO₂>55mmHg

在《论语》的主要内容中，反映出孔子的政治思想核心是（）？

阅读理解

     Register  (注册)  in person, by phone 264-8833 , or by mail. Use the form given.

     178 IN Winchester St. ,Chicago

     Basic Photography This is an eight-hour course for beginners who want to learn how to use a 35mm

camera. The teacher will cover such  areas  as  kinds of film ,light and lenses  (镜头) . Bring your own

35mm  camera  to  class.  Course  charge :  $50. Jan.  10, 12, 17 , 19, Tues. & Thurs. 6 :00 - 8 :00

p. m. Marianne Adams is a professional photographer whose photographs appear in many magazines.

    Understanding Computers This twelve-hour course is for people who do not know much about

computers, but need to leam about them. You will learn what computers are, what they can and can't

do, and how to use them. Course charge: $75. Equipment charge :  $10. Jan. 14 ,21 ,28 , Sats.

7 : 00 - 9 : 00  pm. Joseph  Saimders is a professor of Computer Science at New Urban University.

He has over twelve years of experience in the computer field.

    Stop Smoking Do you want to stop smoking? Have you already tried to stop and failed? Now it's the

time to stop smoking using the latest methods. You can stop smoking, and this twelve-hour course will

help you  do  it. Course  charge :  $30. Jan. 4, 11, 18 , 25 , Weds. 4 : 00  - 7 : 00  pm  Dr John  Goode  

is  a practicing psychologist  (心理学家) who has helped hundreds of people stop smoking.

     Typing This course on weekdays is for those who want to learn to type,as well as those who want to

improve their typing. You are tested in the first class and practice at one of eight different skill levels. This

allows you to learn at your own speed. Each program lasts 20 hours. Bring your own paper. Course

charge :  $125. Materials charge: $25. Two hours each evening for two weeks. New classes begin every

two weeks. This course is taught by a number of business education teachers who have successfully taught typing courses before.

1. All the courses listed above are offered to people_________.

A. who live in the city of Chicago

B. who are free in the evening

C. who want to take some special courses

D. who like to learn something new

2. Of all the courses mentioned in the passage, the shortest one is_________. 

A. Understanding Computers        

B. Basic Photography

C. Stop Smoking                  

D. Typing

3.  There are typing courses__________.   

A. on Saturdays and Sundays

B. from Monday to Friday

C. from Monday to Saturday

D. on each day in the week

4. From the passage we can infer that___________.    

A. Marianne Adams has had many photographs printed in a magazine

B. Joseph Saimders has worked in New Urban University for 12 years

C. Dr John Goode's methods of stopping smoking are very successful

D. there are eight different skill levels for business education teachers