考點:奇數(shù)與偶數(shù)的初步認識,合數(shù)與質(zhì)數(shù)
專題:數(shù)的整除
分析:運用偶數(shù)、奇數(shù)、質(zhì)數(shù)、合數(shù)的意義進行解答即可,質(zhì)數(shù)+質(zhì)數(shù)=奇數(shù)或偶數(shù),偶數(shù)+偶數(shù)=偶數(shù),合數(shù)的因數(shù)個數(shù)比一個質(zhì)數(shù)的因數(shù)個數(shù)多.
解答:
解:A、因為自然數(shù)的個數(shù)是無限的,所以奇數(shù)與偶數(shù)的個數(shù)也是無限的,說法正確.
B、2、3、5都是質(zhì)數(shù),兩個質(zhì)數(shù)的和2+3=5,5是奇數(shù),3+5=8,8是偶數(shù),
所以可能是奇數(shù)有可能是偶數(shù)則兩個偶數(shù)的和一定的偶數(shù),所以題干的說法是錯誤.
C、一個合數(shù)的因數(shù)個數(shù)比一個質(zhì)數(shù)的因數(shù)個數(shù)多,根據(jù)質(zhì)數(shù)只有2個因數(shù),合數(shù)至少3個因數(shù),所以題干的說法正確.
故選:B.
點評:本題考查了偶數(shù)、奇數(shù)、質(zhì)數(shù)、合數(shù)的意義及應(yīng)用.