演讲者应让听众充分相信，他已竭尽全力为他们带来愉悦与教益。

The most successful societies in the world are those that have managed to create a balance between the state, the market, and civil society.

粮食安全始于土壤安全。

随机评估可以帮助我们了解发展中哪些措施有效，哪些无效。