Experts say it is tougher to distinguish oneself in a school-affiliated extracurricular activity that is common among high school students than it is to stand out while doing an uncommon activity.
专家们说,在高中生中常见的学校附属课外活动中脱颖而出,比在从事不常见的活动时脱颖而出更难。
作 "say" 的宾语从句,引导词 that 被省略(零引导)。从句内部为 "it is tougher... than it is..." 比较结构,形式主语 it 指代两个不定式短语。从句完整包含主谓宾及比较成分。