The sour taste is the most refreshing taste in summer, but it’s not very refreshing during those days! Instructor Qian is our instructor for the short but long military training. He is a very serious person. Hidden under his military cap is a face that is darker than the blackest student in our class. "Stand at attention, take a rest..." I originally thought it was the simplest and most ordinary action, but in Qian's case, The instructor's repeated commands no longer seem to be that way, but complex and sacred!