垫片系数m是针对法兰在操作状态下,为确保密封面具有足够大的流体阻力,而需作用在垫片单位_密封面积上的压紧力与流体_压力的比值,垫片愈硬,m愈()。
参考答案:大
在甲型H1N1 流感面前,人们应该积极主动应对,化信心为力量。下列名言中符合意识能动性原理的是 [ ]
①信心比黄金更重要
②我们唯一恐惧的就是恐惧本身
③问题与解决问题的方法是同时产生的
④事不必难,知难不难
A.①②③
B.②③④
C.①③④
D.①②④
Guangzhou (Xinhua)——12 people were killed and 20 injured early yesterday morning when they jumped from a burning train car into the path of an oncoming goods train in Southern China. When No. 247 Wuchang——Guangzhou passenger train was passing the Dayaoshan Tunnel in Guangdong Province, South China at 00 :17 yesterday, a fire caused by passengers' smoking broke out on No. 17 car. They wanted to extinguish fire. As the train stopped some frightened passengers jumped from windows. 12 people were crushed to death and 20 others injured by a northward passing goods train(No. 1766)。
1. In which direction did the passenger train travel?
A. Northward. B. Southward. C. Eastward. D. Westward.
2. When did the accident happen?
A. At 00:17 am. B. At 00:17 pm.
C. At seventeen past one. D. At seventeen to one.
3. Where did the accident happen?
A. In Wuchang. B. In Guangzhou.
C. In Hubei. D. In Guangdong.
4. What was the cause of the fire?
A. A heavy rain. B. High temperature. C. Carelessness. D. Fear.