我国文物藏品分为（）。
A.珍贵文物和一般文物
B.一级、二级和三级文物
C.重要文物和较重要文物
参考答案：A
You can help your body by drinking water when you're thirsty _____ drinking extra water when it's warm out. [ ]
A. but
B. while
C. or
D. and
近视力测定有什么意义？
