【单选题】求解静定桁架结构内力时节点法是以()为研究对象,用平面汇交力系的平衡方程求解杆件内力的。
【简答题】已知某厂商的生产函数为 Q=f(K,L)=15KL/(2K+L)。求: (1)劳动的边际产量(MPL)函数和劳动的平均产量(APL)函数; (2)劳动边际产量的增减性。
【单选题】You love peanut butter. You hear on the news that 50 % of the peanut crop in the South has been wiped out, which will cause the price to double by the end of the year. As a result,
A.
your demand for peanut butter will increase by the end of the year.
B.
your demand for peanut butter increases today.
C.
your demand for peanut butter falls as you look for a substitute good.
D.
you decide to give up peanut butter completely.
【单选题】Conversation Two 7
A.
To register for a winter-vacation course
B.
To look for a new place to stay
C.
To complain of the warden’s carelessness
D.
To find two or three students to share an apartment
【单选题】You love peanut butter. You hear on the news that 50 percent of the peanut crop in the South has been wiped out by drought, and that this will cause the price of peanuts to double by the end of the y...
A.
your demand for peanut butter increases today.
B.
your demand for peanut butter decreases as you look for a substitute good.
C.
your demand for peanut butter shifts left today.
【多选题】关于静定平面桁架的说法,正确的有( )
A.
桁架杆件都是二力杆,杆件的轴力可以是拉力或压力
B.
桁架杆件的轴力必须是压力,横截面应力分布均匀
【单选题】静定平面桁架中的杆件在受力时其内力为()
【单选题】“辛辛苦苦,过舒服日子;舒舒服服,过辛苦日子。上帝是公平的,当关上一扇门后,就会为你打开另一扇门。”这说明()
A.
积极适当地在艰苦环境中锻炼自己,对于自己的一生肯定有益
B.
要么过辛苦日子,要么过舒服日子,只能选择一种
【多选题】关于静定平面桁架的说法,不正确的有( )。
B.
桁架杆件的轴力必须是压力,横截面应力应分布均匀