【单选题】以下哪一项需要基于悲观、乐观、预计期限的加权平均值来估计完成任务的时间?
【简答题】Why did the Kentucky Cave Wars happen?
【判断题】每一瞬时,平面图形对于固定参考系的角速度和角加速度与平面图形绕任选基点的角速度和角加速度相同。
【判断题】每一瞬时,平面图形对于固定参考系的角速度和角加速度与平面图形绕任选基点的角速度和角加速度相同。()
【单选题】Why did man have to track his target at a close range when using a short bow?
A.
Because it was too heavy.
B.
Because it did not bend easily.
C.
Because it did not shoot far.
D.
Because its string was short.