题干
It is said that students like to talk with friends online.
A：two-thirds
B：two-three
C：two-third
答案(点此获取答案解析）
A
It is said that students like to talk with friends online.
A：two-thirds
B：two-three
C：two-third
中，
，
是等比数列，且
，则
的值为（ ）