正式沟通的优点有（） ["约束力强","沟通速度快","易于保密","具有权威性","失真少"]
简述营养繁殖的缺点
It （）quite a few years （）the accused was declared innocent and set free． ["was；since","is；that","will be；when","was；before"]
简述道路的选取原则。
正式权力具有以下几个特点（） ["上级委任","强制实施","不稳定性","等级式","成员授予"]
如何分析样本误差并推断总体误差？
