能省的就省当用的还是得用的英文

save what you can but use what you must

• 能省的就省:    economize wherever ...
• 当:    proper; right
• 用:    40分钟跑完全程 run the c ...
• 的:    4次方是 The fourth po ...
• 还是:    still; nevertheles ...
• 得用:    capable; competent