Unobservable
a. 难以察觉的；注意不到的；不可见的
✅ 同义词
🗣️ 情景例句
There's a phone number --
这有电话号码，
I ought to tell him the whole story.
我应该告诉他整个事情的始末。
Excuse me. What's the time, please?
对不起，请问几点了？