如图,设重物Q静止作用于梁上截面C处时,截面C和B处的静位移分别为△ Cst 和△ Bst ,现考虑重物Q由高度H处自由下落,则下列结论中哪些是正确的? (1)求梁AB的动荷应力和求弹簧中的动荷应力,所取动荷因数K d 的值相同; (2)求梁AB中的动荷应力和求弹簧中的动荷应力,所取动荷因数K d 的值不同; (3)求梁上截面c处的动荷应力,公式 中的静位移△ st 应取截面C的值△ Cst (4)求梁上截面C处的动荷应力,公式 中的静位移△ st 应取
【简答题】听力原文: Despite widespread medical opinion that alcoholic beverages may pr heart disease, a leading medical expert is advising: don't start drinking just yet. Anybody who's ever worked in a hospita...
【单选题】Exercise 2: Please Choose the best topic sentences for the body paragraphs based on the outline below. Alcoholic beverages should be banned. In my opinion, alcoholic beverages should be banned from co...
A.
Drinking and driving can be deadly.
B.
Alcoholic beverages on college campuses should be banned because drinking and driving can be deadly.
C.
Besides the academic reason, alcoholic beverages on college campuses should be banned because drinking and driving can be deadly.