You may avoid suffering and sorrow if you don't risk, but you simply cannot learn, feel, change, grow, love, live. The greatest hazard in life is to risk nothing. The person who risks nothing, does nothing and has nothing. Only a person who risks is free - Bob Proctor, Motivational Coach
關鍵詞:金屬轉子流量計,金屬管轉子流量計,金屬管浮子流量計