【单选题】The buses run less ___ on Sundays.
【简答题】用卡氏定理求 A 截 面的挠度( EI 已知)。
【单选题】悬臂梁受力如图示,应变能为【图片】 ,弯矩方程为M(x),弯曲刚度为EI,应用卡氏第二定理求截面B的挠度【图片】 ,以下答案正确的是( )。 【图片】【图片】
【单选题】One reason why the demand for gasoline is inelastic is because
A.
substitutes for gas abound.
B.
substitutes for gas are hard to find.
C.
gasoline is a luxury item.
D.
people have a long time to shop around for automobiles that use less gas.
E.
buses run on diesel fuel rather than gasoline.
【单选题】The buses run less _______ on Sundays.
【单选题】图示简支梁在截面 C , D 处受集中力作用,用卡氏定理求挠度,下列结论中哪些是正确的 ? (1) 梁 AB 的变形能 U=5P 2 a 3 /6EI ; (2) 挠度 y C =y D = Ð U/ Ð P =5Pa 3 /3EI 。
【单选题】According to the passage, modern variants on the story generally ______.
A.
portray Cinderella as a successful professional
B.
imply that Cinderella will become a real princess
C.
reflect children's beliefs and aspirations
D.
make concessions to modern women's lives