【简答题】当临界应力σ cr 小于______时,轴心受压杆属于弹性屈曲问题。
【单选题】It is believed tha if a book is __________, it will surely __________ the reader. [ ]
B.
interesting; be interested
C.
interested; be interesting
【单选题】车用自动变速器主要是依据( )两个信号来自动变换各前进档。
【单选题】若σ cr 表示细长柱的临界应力,则下列结论中______是正确的。
A.
σ cr 与临界荷载和柱的横截面积有关,与柱体材料无关
B.
σ cr 与柱的长细比λ有关,与柱的横截面积无关
C.
σ cr 与柱体材料和横截面的形状尺寸有关,与其他因素无关
D.
σ cr 的值不应大于柱体材料的比例极限σ p
【判断题】Ionesco believed that not only absurd plays can reflect the mechanical nature of modern civilization. ____ Multiple Choice:
【判断题】临界夜长比临界日长对植物开花更为重要。( )
【单选题】No one believed his reason for being late he was caught in a traffic jam, made him embarrassed.
【简答题】(3分)临界夜长(critical dark length)