【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"))

As a teen, you're going through ( ) changes in your body. As a teen, you're going through ( ) changes in your body.

There are ________ (各种各样的) teen magazines in the bookstore.

Nearly every teen can ________ from job experience.

As a teen, you're going through ( ) chan...hanges in your body.

智慧职教: Are you or your teen addicted to your cellphone?

If a teen thinks that therapy could help, who might he or she NOT ask to find a therapist?

Good luck is when an _______ comes along and you're prepared for it A: surface B: teen C: wonder D: opportunity

The article would most likely be found in ______ A: a children’s magazine B: a spoils magazine C: a teen magazine D: a family magazine

Who is Patrick Ryan（） A: He is the editor-in-chief of "Twilight". B: He is the editor-in-chief of Granta. C: He is the editor-in-chief of One Teen Story. D: He is the editor-in-chief of One Story.