Find the one that must be changed.
28. Machines need energy to function, whether it is animal or human muscle, wind or waters currents, or heat-generated energy, such as steam.
I know waters is incorrect, but why whether is used here? There is a choice between more than two things(...animal or human muscle, wind or waters currents, or heat-generated energy...). Shouldn't it be whichever?
I cann't agree with u.
Note that it is NOT a choice between "human" and "animal", but a choice between "muscle", "currents", and "heat-generated energy".
-whichever it is muscle, currents or heat-generated energy
-whether it is muscle, currents or heat-generated energy
Which one is better? Don't u think whether should only be used when choosing between two?