皮皮学，免费搜题
登录
搜题
【简答题】
试述自动空气断路器的主要作用?
拍照语音搜题，微信中搜索"皮皮学"使用
参考答案：
参考解析：
知识点：
皮皮学刷刷变学霸
举一反三
【单选题】Which of the following statements describes the definition of systematic sampling?
A.
Every nth number of the population is selected
B.
Every element of one definable sub-section of the population is selected
C.
Each element of the population has an equal chance of being chosen
D.
This method needs investigating prior information in advance
【多选题】Which of the following statement about systematic sampling is/are true?
A.
Sample members are selected from the sampling frame according to a random starting point and a fixed, periodic interval.
B.
The interval, called the sampling interval Kth, is calculated by dividing the population size N, by the desired sample size n. Kth=N/n
C.
The starting point can be obtained in a lottery method.
D.
The starting point can be obtained by using a random number table.
E.
It is a method belonging to non-probability sampling.
【简答题】90°偏刀主要用来车削（）的工件。
相关题目：