Some people won't realize the importance of their health _______ they have lost it. [ ]

A. after

B. when

C. until

D. as

环境因素按其属性可分为（）

A.地理性、化学性、生物性

B.化学性、物理性、地理性

C.生物性、物理性、地理性

D.化学性、地理性、地质性

E.物理性、化学性、生物性