普中单片机60秒倒计时答:include <reg51.h>typedef unsigned int u16;typedef unsigned char u8;sbit LSA=P2^2;sbit LSB=P2^3;sbit LSC=P2^4;u8 code smgduan[17]={0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f,0x77,0x7c,0x39,0x5e,0x79,0x71};//显示0~F的值u8 sec=60,cnt=0;void delay(...