若碳原子的质量为a克,A原子的质量为b克,则A原子的相对原子质量为( )
A:12ba
B:12ab
C:a12b
D:b12a
芜湖地处长江中下游,水资源丰富,素有“江南水乡”之美称.据测量,仅浅层地下水蕴藏量就达56000万m3,用科学记数法记作 ( )
They had a difficult time _______ in the village at first, but soon they got over it.