Question

下列說(shuō)法正確的是（　�。�

A．有理數(shù)的絕對(duì)值為正數(shù)

B．只有正數(shù)或負(fù)數(shù)才有相反數(shù)

C．如果兩數(shù)之和為0，則這兩個(gè)數(shù)的絕對(duì)值相等

D．如果兩個(gè)數(shù)的絕對(duì)值相等，則這兩個(gè)數(shù)之和為0

Answer 1

分析：根據(jù)0的絕對(duì)值為0對(duì)A進(jìn)行判斷；根據(jù)0的相反數(shù)為0對(duì)B進(jìn)行判斷；根據(jù)絕對(duì)值與相反數(shù)的定義對(duì)A進(jìn)行判斷；根據(jù)兩個(gè)數(shù)的絕對(duì)值相等，則這兩個(gè)數(shù)相等或和為0對(duì)D進(jìn)行判斷．

解答：解：A、0的絕對(duì)值為0，所以A選項(xiàng)錯(cuò)誤；
B、0的相反數(shù)為0，所以B選項(xiàng)錯(cuò)誤；
C、如果兩數(shù)之和為0，則這兩個(gè)數(shù)的絕對(duì)值相等，所以C選項(xiàng)正確；
D、如果兩個(gè)數(shù)的絕對(duì)值相等，則這兩個(gè)數(shù)相等或和為0，所以D選項(xiàng)錯(cuò)誤．
故選C．

點(diǎn)評(píng)：本題考查了絕對(duì)值：若a＞0，則|a|=a；若a=0，則|a|=0；若a＜0，則|a|=-a．也考查了相反數(shù)．