Unobservable
a. 难以察觉的；注意不到的；不可见的
✅ 同义词
🗣️ 情景例句
Although we hadn't met for 25 years, I recognized him the minute I saw him.
尽管我们有25年未见面了，我一看见他就认出来了。
If you don't like it ,I wish you would say so.
如果你不喜欢，我想要你这样说。
The number 13 bus will take you to the hospital.
13路车会带你去医院。