"Στερεό,υγρό και αέριο."

[Edwin904807]

It counts a space after Στερεό as a mistake... Instead it wants a comma directly after, and without a space start with υγρό. That seems like a mistake :)

[tcamundsen]

Really annoying

[cwhaught]

I had the exact same issue

[alainPierrot]

could it be the adjective, so "gaseous"?

[fazulakis]

I agree

[thoas]

I would also interpret it as an adjective.

[Qazimustuf1]

Thx. Let me try

[Mary150457]

They are adjectives used as nouns, this is why gas is the correct choice. Otherwise it would have been accompanied by a noun e.g. gaseous state, liquid luck (couldn't resist!) etc. This is also why they are neutral.

[Qazimustuf1]

Thanks all fellows to solve the ambiguity

[Meowe3]

Do they not put spaces after commas in Greek?

[jeanprendiville]

Remember the days of the "cats whiskers" subsequently the solid state radio or "stereo"?

[robert672165]

Learn something every day. I thought it referred only to sound or vision.
stereo- a combining form borrowed from Greek, where it meant “solid”, used with reference to hardness, solidity, three-dimensionality in the formation of compound words: stereochemistry; stereogram; stereoscope.

[NelZeroTwo]

Spaces are not needed after commas?