问题 单项选择题

某220kV变电所,最终规模为2台180MVA的主变压器,额定电压为220/110/35kV,拟在35kV侧装设并联电容器进行无功补偿。请回答下列问题。

若本所每台主变压器安装单组容量为3相3.5kV,12000kvar的电容器两组,电容器采用单星形接线,每相由10台电容器并联后再2组串联而成,请计算每单台容量为:()

A.500kvar

B.334kvar

C.200kvar

D.350kvar

答案

参考答案:C

阅读理解

阅读理解

     Japanese high school students either walk or ride bicycles if the distance is not too great. In other cases, students must take public buses and trains. After junior high school, students attend schools based on their high school entrance examination scores. So some students travel a great distance to attend the school.

     ◆________

     The school day begins at 8:30. Then students assemble in their homeroom classes for the day's studies. Each homeroom has an average of 40-45 students. Students stay in their homeroom classrooms for most

of the school day. Only for physical education, laboratory classes, or other subjects requiring special

facilities(设备) do students move to different parts of the school. Between classes and at lunchtime,

classrooms can be noisy, lively places. Some schools may have a cafeteria(自助餐厅), but most do not.

In most schools, students bring a box lunch from home, prepared by the mother in the early morning hours.

     Japanese students spend 240 days a year at school, 60 days more than American students. Students in high schools take three years' each of the following subjects mathematics, social studies, Japanese, science, and English. Other subjects include physical education, music, art, and moral(道德的) studies. All the

students in one grade level study the same subjects. Given the number of required subjects, electives

(选修科目) are few.

     ◆Afterschool Activities

     Club activities take place after school every day. Students can join only one club, and they rarely

change clubs from year to year, so the clubs are relatively stable. Clubs are made up of sports clubs

(baseball, soccer, judo, kendo, etc.) and culture clubs(English, broadcasting, science, etc.). New students usually are encouraged to select a club shortly after the school year begins in April. Clubs meet for two

hours after school each day and many clubs continue to meet during school vacations.

1. Most Japanese high school students often have their lunch________.

A. in restaurants  

B. in school cafeterias

C. at home    

D. in homeroom classrooms

2. Students in the USA go to school________days a year.

A. 180  

B. 200  

C. 240  

D. 300

3. The underlined word "rarely" in the fourth paragraph means "________".

A. always  

B. never  

C. seldom  

D. often

4.From the passage we know that________.

A. there are less than 40 students in each class in Japanese high schools

B. students must stay in homeroom classrooms for physical education

C. there are few subjects for students to choose except the required ones

D. there will not be any club activities during school vacations

5. The best subtitle for the second and third paragraphs may be "________".

A. At school  

B. In class

C. Subjects  

D. Homerooms

判断题