标出下列物质中各元素的化合价.
氯化锌 ____ ,钠____ ,氢氧化钠 ____ .
A: I wear size 35 shoes.
B: I wear size 37 shoes. Your feet are ____ than mine.
已知a=0.70.6,b=0.6﹣0.6,c=0.60.7,则a,b,c的大小关系是( )