但如果取第二个定义它就不再无形2，无法感知，不能观察。

But it's not invisible if we mean definition no. 2 can't be sensed. Can't be observed.

youdao

但如果取第二个定义它就不再无形2，无法感知，不能观察。

But it's not invisible if we mean definition no. 2 can't be sensed. Can't be observed.

youdao