如有以下代码段,则输出结果是: char ch1,ch2,ch3,ch4; ch1 = '\\'; ch2 = '\?'; ch3 = '\101'; ch4 = '\x61'; printf("ch1 = %c,ch2 = %c\n",ch1,ch2); printf("ch3 = %c,ch4 = %c\n",ch3,ch4); printf("ch3 = %d,ch4 = %d\n",ch3,ch4); 输出结果是:_______________(1) _______________(2) _______________(3)