Guo Biting's back is really thin It's a beauty at a glance. Guo Biting's back is really slender, and she is a beauty at a glance. Guo Biting's back is really slender, and she is a beauty at a glance. Guo Biting's back is really slender, and she is a beauty at a glance. Guo Biting's back is really slender, and she is a beauty at a glance.