11[解决办法]
$ awk 'BEGIN{FS="[解决办法]"}{if(NR==FNR)a[$1]=$0;else b[$1$2]=$3FS$4}END{for(i in a){for(j in b){if(i>substr(j,0,11) && i<substr(j,12,11)){print a[i]"[解决办法]"b[j];break;}}}}' a.txt b.txt
