invisible
/ˌɪnˈvɪzəbəl/
impossible or nearly impossible to see; imperceptible by the eye
中文释义:看不见的;无形的
Some gases are invisible but can be detected by special instruments.
有些气体看不见,但可以通过特殊仪器检测到。
The invisible hand of the market guides economic decisions.
市场这只看不见的手引导着经济决策。