The most common, is community acquired pneumonia, and it's called that when a person gets sick outside of a hospital or healthcare setting.

最常见的是社区获得性肺炎，指患者在医院外或健康机构之外发病。

Why do some non-native speakers of English claim that it's a difficult language to learn, while infants born into English-speaking communities acquire their language before they learn to use forks and knives?

为什么一些非英语母语的人说这是一门难学的语言，但是英语母语环境下的婴儿在他们学会使用刀叉之前就掌握了英语？