—— 请按键盘 空白键 开始游戏 ——

心有成见,就好像用水浇石头,水一点都进不去;对事理不能领悟,则拘泥而不变通,一点都转动不得。
Food security begins with soil security.
The value chain is the set of activities through which a product or service is created and delivered to customers.