简介:If he hadn't listened attentively, he wouldn't have noticed it. Li Dao took Qin Er and followed the place where the sound came from. They walked through the woods and came to a narrow valley. There was a cave in the valley, and there was an arc-shaped vent above the cave entrance. , there was actually a huge flow of air pouring in from this vent, and then flowing back out of the cave, which was very strange.