【单选题】一般来讲,谷物中的第一限制性氨基酸为( )。
【简答题】在图中,质量为m=12kg、长为l=0.75m的均质杆AB,铰接于固定点A,受到力偶矩M=30N·m的力偶作用,杆的B端与刚性系数k=80N/m的弹簧相连。假设杆从θ 0 =30°时无初速释放,弹簧在杆的初始位置无变形。运动过程中,弹簧借助小轮C保持水平。求当θ=60°时杆的角速度。
【简答题】What is a generally suggested minimum sample size for a group in a causal-comparative study or correlation study?
【单选题】When economists talk about growth in the economy, they measure that growth as the
A.
absolute change in nominal GDP from one period to another.
B.
percentage change in nominal GDP from one period to another.
C.
absolute change in real GDP from one period to another.
D.
percentage change in real GDP from one period to another.
【单选题】Creating a new chip design or a new software program is a ____ effort that relies almost exclusively on well-paid domestic workers.
【简答题】Why the manufactures did not accept the new design.
【简答题】一般来讲,谷物中的第一限制性氨基酸为( )。