on-topic
/ɒnˈtɒpɪk/adjective & adverb
- (especially of posts on an Internet message board) relevant to the subject in question（尤指因特网留言板上的帖子）与主题有关的（地）：
as adj. on-topic contributions to the discussion与所发讨论有关的帖子
as adv. I'll do my best to stay on-topic.我将尽最大努力做到不跑题。