Unobservable
a. 难以察觉的；注意不到的；不可见的
✅ 同义词
🗣️ 情景例句
How many days will it take for my mail to reach its destination?
我的信件到达目的地要用几天？
If wishes were horses,beggars might ride.
愿望若是马，乞丐也可乘；愿望难成事实。
Everybody around me was smoking and I felt extremely uncomfortable.
我周围的每个人都在吸烟，我感到非常不自在。