1、单选题：
Which of the following belongs to continuous numerical variable?（ ）
选项：
A:gender.
B:country
C:age
D:blood type
答案: 【age】

2、单选题：
What is the range of probability P for a random event? （ ）
选项：
A:-1≤P≤0
B:P =1
C:0≤P≤1
D:-1≤P≤1
答案: 【0≤P≤1】

3、单选题：
Which of the following cannot be avoided during sampling? （ ）
选项：
A:sample size is too small
B:personal error
C:sample size is too large
D:sampling error
答案: 【sampling error】

4、单选题：
Low, median and high belong to _____? （ ）
选项：
A:Raw data
B:Ordering data
C:Measuring data
D:Counting data
答案: 【Ordering data】

5、单选题：
Which of the following belongs to discrete numerical variable ________? （ ）
选项：
A:Weight
B:Number of children in a family
C:Height
D:Cancer degree
答案: 【Number of children in a family】

6、单选题：
Which one of the following variables is not categorical? （ ）
选项：
A:Age of a person.
B:Gender of a person: male or female.
C:Choice on a test item: true or false.
D:Marital status of a person (single, married, divorced, other)
答案: 【Age of a person.】

7、单选题：
Which of the following belongs to the measurement data ________. （ ）
选项：
A:WBC counts
B:gender
C:blood type
D:curative effect
答案: 【WBC counts】

8、单选题：
Which of the following belongs to categorical variable ________. （ ）
选项：
A:gender of people in a specific region.
B:heart rate
C:score of IQ
D:days staying in hospital
答案: 【gender of people in a specific region.】