音标: 英 ['ki:stəʊn] 美 [ˈkiˌston]
1. What you tried, a keystone cop would have spotted.
你之前的手法 是个警察都能看出来
2. Just dealing with some middle eastern keystone cops out at the gate.
刚在大门那儿处理一些 不开窍的中东警察的事儿
3. However, a thorough examination led me to what I'm calling the keystone of my diagnosis.
然而 全面的检查让我 找到了诊断的核心所在
4. If we don't act now, I believe that we will lose many keystone species, such as the orangutan.
现在不行动的话 我们就会失去 很多重要物种 比如大猩猩