0 Infrared light is a type of light that feels warm but cannot be seen: --
1 describing light at the red end of the spectrum (= set of colors into which light is separated), which cannot be seen by human beings, and which gives out heat --
We can complete it step by step however long the road is and it can't be completed however short the road is if you don't even mark your footprint.
Vi kan slutföra det steg för steg hur lång vägen än är och den kan inte slutföras hur kort vägen än är om du inte ens markerar ditt fotavtryck.