In cases like this, it may become less clear what the possessive is determining: is the topic you train "adult('s/s') English" or "English"? There are many strategies for avoiding the additional awkwardness with the possessive: 知乎，让每一次点击都充满意义 —— 欢迎来到知乎，发现问题背后的世界。 Recognize poem: My gentle child, behold this horse, / a noble animal https://www.adult-vod.tv/