【单选题】生成如下数据框的语句是? weight height gender age 1 80 180 male teen 2 75 170 male teen 3 60 165 female adult 4 52 150 female adult A. X ,gender=c("male", "male", "female", "female"),age=c("teen","teen","adult","adult")) B. X ,gender=c("male", "male", "female", "female"),age=c("teen","teen","adult","adult")) C. X ,gender=c(male, male, female, female),age=c(teen,teen,adult,adult)) D. X ,gender=c("male", "male", "female", "female"),age=c("teen","teen","adult","adult"))

Number the events in the order they happen. A: The male student stands up and leaves the table. B: The male student thanks the female student. C: They introduce themselves to each other. D: Two students are studying in the library. E: They shake hands with each other. F: The female student picks up the wallet and runs after the male student.

What does the author say about today’s college experience? A: It is different for male and female students. B: It is not the same as that of earlier generations. C: It is more exhausting than most women expect. D: It is not so satisfying to many American students.

The number of male students are largely more than female students in the major of____。（ ） A: music B: fine art C: dance D: drama

'surplus male and female' means single or unmarried male and female.