数学求平均值公式简介：When he raised his head again, he had a resolute look on his face and slightly excited eyes. At this moment, he was no longer a doctor, but a messenger with an important order and a general who was about to travel far.
When he raised his head again, he had a resolute look on his face and slightly excited eyes. At this moment, he was no longer a doctor, but a messenger with an important order and a general who was about to travel far.
