C B 分析:根據(jù)最大公約數(shù)和最小公倍數(shù)的意義可知;最大公約數(shù)是兩個數(shù)的公有的質(zhì)因數(shù)的乘積,最小公倍數(shù)是兩個數(shù)共有的質(zhì)因數(shù)和各自獨有的質(zhì)因數(shù)的乘積,如果自然數(shù)C是B的5倍,B和C是倍數(shù)關(guān)系,據(jù)此解答 解答:自然數(shù)C是B的5倍,則B與C的最小公倍數(shù)是C,最大公因數(shù)是B; 故答案為:C,B 點評:主要考查倍數(shù)關(guān)系的最大公約數(shù)和最小公倍數(shù)的求法:較大的數(shù)是兩個數(shù)的最小公倍數(shù),較小的數(shù)是兩個數(shù)的最大公約數(shù).