Unobservable
a. 难以察觉的；注意不到的；不可见的
✅ 同义词
🗣️ 情景例句
That's irrelevant.
那不相干。
Oh, really? Where did you go?
哦，真好？去哪儿了？
I like reading English books, but they're sometimes rather hard.
我喜欢看英语书，但有时候英语书相当难读。