Students whose extracurricular activity has benefited their community are likely to win a scholarship.
其课外活动有益于其社区的学生有可能获得奖学金。
限制性定语从句修饰先行词"Students",关系代词"whose"在从句中作定语修饰"extracurricular activity",从句主干为"extracurricular activity has benefited their community",无逗号隔开、限定了哪类学生,删去则"Students are likely to win a scholarship"语义过于宽泛。