Unobservable
a. 难以察觉的；注意不到的；不可见的
✅ 同义词
🗣️ 情景例句
We really don't have to be overly concerned.
我们真的不需要过分担心。
What time are you leaving?
你几点钟走？
The development of films with sound became a problem for Chaplin.
有声电影的研制对卓别林来说就成了问题。