题干
—How do you keep healthy?
—I take some ．
A：experience
B：service
C：surprise
D：exercise
答案(点此获取答案解析）
D
—How do you keep healthy?
—I take some ．
A：experience
B：service
C：surprise
D：exercise
，
，且
，
，
成等比数列，则
（ ）