指出下列情况分别属于系统误差还是随机误差（1）天平使用前未调平衡（）（2）千分尺零点

阅读理解。

      American schools’ beginning is in September after a long summer holiday. There are two terms in a

school year. The first term is from September to January, and the second is from February to June. Most American children begin to go to school when they are five years old. Most students are seventeen or

eighteen years old when they finish high school.

     High school students take only four or five subjects each term. They usually go to the same classes e

very day, and they have homework for every class. After class they do many interesting things.

After high school, many students go to college. They can go to a small one or a large one. They usually

have to give a lot of money. So many college students work after class to get the money for their studies.

1. How many terms are there in a school year in America ?

A. Four    

B. One    

C. Three    

D. Two

2. The first term is ______.

A. from February to June          

B. from January to September  

C. from June to February          

D. from September to January

3. When a child is ______ years old he or she can go to school.

A. five    

B. four    

C. seven    

D. six

4.How many subjects do the high school students take each term ?

A. As many as they like.    

B. Five.  

C. Four.    

D. Four or five.

5. Why do many college students have to work after class ?

A. Because some work is helpful to their studies.  

B. Because the teachers ask them to do so.

C. Because they like to work very much.  

D. Because they need to get money for their studies.

跨越道路街道的低压接户线，至路面中心的垂直距离，胡同（里弄、巷）应不小于（）。

A.3m

B.3.5m

C.4.5m

D.6m

工作性质，一般通过职业活动的对象、从业方式等的不同予以体现。

对于社会工作伦理和社会工作研究二者的关系，正确的理解是( )。

A．必须在研究中彰显社会工作伦理

B．为了研究任务的完成，可以舍弃社会工作伦理

C．为了研究任务的完成，可以部分舍弃社会工作伦理

D．社会工作伦理和社会工作研究没有任何关系

E．在社会工作研究中，可以根据实际情况，改变社会工作伦理

洋务运动秉承“中体西用”思想，是统治阶级的自救运动。