Xue Jianqiang was a little frustrated. Although he was not very familiar with the warfare methods of this era, he could see that attacking in this season of sparse vegetation and icy weather was not easy. What's easy? Spring and summer are the peak periods of guerrilla activities. In autumn and winter, it is the Japanese army's turn to show its strength, especially in winter, when the grass and trees dry up, making it difficult to hide. Food was scarce. Those days were very difficult.