素数只有2是偶数,所以只能是2＋997＝999不然两个奇数相加肯定是偶数,不会是999的.下面是1000以内的素数表：2,3,5,7,11,13,17,19,23,29,31,37,41,43,47,53,59,61,67,71,73,79,83,89,97,101,103,107,109,113,127,131,1...