问题 问答题 论述题

叙述机组AGC投、退入条件及操作。

答案

参考答案:

AGC投入条件:

(1)AGC的投入按中调值班员的命令执行。

(2)AGC投入前应检查确认协调投入,机组运行稳定。

(3)AGC信号可用。

(4)机组负荷在规定范围。

投入操作:在“负荷控制中心”按下“AGC投入”按纽即可。AGC投入后,监盘人员应注意根据负荷情况适当修改主汽压力设定值,保持机组各参数的稳定。

AGC退出条件:

(1)AGC的退出按中调值班员的命令执行。

(2)协调控制退出。

(3)ADS指令信号质量坏或ADS指令信号10s前后偏差大。

(4)阀门活动实验。

(5)发电机主开关断开。

退出操作:在“负荷控制中心”按下“AGC切除”按纽即可。

单项选择题

As Philadelphia grew from a small town into a city in the first half of the eighteenth century, it became an increasingly important marketing center for a vast agricultural hinterland. Market days (1) the crowded city even more crowded, as farmers from within a (2) of 24 or more kilometers brought their sheep, vegetables, cider and other products for direct sale to the (3) . The High Street Market was continuously (4) throughout the period until 1736, (5) it (6) from Front Street to Third. By 1745 New Market was opened on Second Street. The next year the Callow Hill Market began (7) .

Along with market days, the (8) of twice-yearly fairs persisted in Philadelphia (9) after similar trading days had been discontinued in other colonial cities. The (10) provided a means of bringing handmade goods from (11) places to would-be buyers in the city. Linens and stockings from Germantown, (12) , were popular items.

Auctions were another popular (13) of trade. Because of the competition, retail (14) opposed these as well as the fairs. (15) governmental attempts to eradicate fairs and auctions were less than successful, the ordinary (16) of economic development was on the merchants’side, as increasing business specialization became the (17) of the day. Export merchants became differentiated from their importing counterparts, and specialty shops began to appear (18) general stores selling a variety of goods.

One of the reasons Philadelphia’s merchants prospered was because the surrounding area was undergoing tremendous economic and demographic growth. They did their business, (19) , in the capital city of the province, (20) to not only the governor and his circle, but citizens from all over the colony.

5()

A.that

B.what

C.how

D.when

单项选择题 A1/A2型题