下列物质中,属于电解质的是( )
A.蔗糖
B.硫酸钡
C.盐酸
D.金属铁
答案:B
Great Britain is one of the countries people drive on the left. [ ]
A. where
B. that
C. which
D. there
暂居外国的本国公民不属于常住居民的统计范围。( )