问题 单项选择题

使气体和固体物料起化学反应,或使气体在静止状态时触媒的影响下彼此起化学反应的设备叫()。

A.釜式反应器

B.管式反应器

C.固定床反应器

D.流化床反应器

答案

参考答案:C

解析:

反应器包括以下4类:

(1)釜式反应器。釜式反应器多设有搅拌装置及传热装置。既可以用于间歇(分批)也可以用于连续操作过程,既可以用单釜也可用多釜连续操作。

(2)管式反应器。管式反应器由单根连续管子或由一根以上的管子平行排列构成。

(3)固定床反应器。使气体和固体物料起化学反应,或使气体在静止状态时触媒的影响下彼此起化学反应的设备。

(4)流化床反应器。流化床反应器是使参与化学反应或触媒的固定颗粒物料处于激烈的运动状态的反应器。

判断题
单项选择题

Who won the World Cup 1994 football game What happened at the United Nations How did the critics like the new play (1) an event takes place, newspapers are on the streets (2) the details. Wherever anything happens in the world, reporters are on the spot to (3) the news.
Newspapers have one basic (4) , to get the news as quickly as possible from its source, from those who make it to those who want to (5) it.
Radio, telegraph, television, and (6) inventions brought competition for newspaper. So did the development of magazines and other means of communication. (7) , this competition merely spurred the newspapers on. They quickly made use of the newer and faster means of communication to improve the (8) and thus the efficiency of their own operations. Today more newspapers are (9) and read than ever before. Competition also led newspapers to branch out into many other fields. Besides keeping readers (10) of the latest news, today’s newspapers (11) and influence readers about politics and other important and serious matters. Newspapers influence readers’ economic choices (12) advertising. Most newspapers depend on advertising for very (13) .
Newspapers are sold at a price that (14) even a small fraction of the cost of production. The main (15) of income for most newspapers is commercial advertising. The (16) in selling advertising depends on a newspaper’s value to advertisers. This (17) in terms of circulation. How many people read the newspaper
Circulation depends (18) on the work of the circulation department and on the services or entertainment (19) in a newspaper’s pages. But for the most part, circulation depends on a newspaper’s value to readers as a source of information (20) the community, city, county, state, nation, and world—and even outer space.

[A] make [B] publish [C] know [D] write