【简答题】热虹吸管(又称重力热管)是一种封闭、竖直放置的容器,其沸腾段吸收的热量在其冷凝段放出,如附图所示。今用抛光的不锈钢制成一热虹吸管,d=20mm、l b =20mm,l c =40mm,l i =40mm。设1.013xl0 5 Pa压力下的饱和水在沸腾段沸腾.热流密度q是临界热流值的30%。 求沸腾段的平均壁温t wb
【单选题】A greater number of newspapers are sold in Town S than in Town T. Therefore, the citizens of Town S are better informed about major world events than are the citizens of Town T. Each of the following,...
A.
Town S has a larger population than Town T.
B.
Most citizens of Town T work in Town S and buy their newspapers there.
C.
The average citizen of Town S spends less time reading newspapers than does the average citizen of Town T.
D.
A weekly newspaper restricted to the coverage of local events is published in Town S.
E.
The average newsstand price of newspapers sold in Town S is lower than the average price of newspapers sold in Town T.