Marked wrong for: "The telephone cable is long?" Other translations may well be more natural, but given that this kind of translation has been accepted for many other phrases / sentences, this seemed a bit of an unecessary nuisance.
Is this a transAtlantic cable we're talking about? Around here (U.S.) we usually say phone cord. (if talking to the generation that remembers phones with cords)
I found "cordon" for "cord"; then, I found that "cabluri" means "wiring", thus, "cordon" would not apply to such "electronic" uses. (But a native speaker is welcome to chip in here.)
DL doesn't recognise that if shortened to 'phone then the apostrophe to indicate the omission of the tele is a valid and older option - though sussex uni states "Writing things like... 'phone will, not to mince words, make you look like an affected old fuddy duddy who doesn't quite approve of anything that's happened since 1912. nothwithstanding my fuddy duddy-ness I should not be marked incorrect for my 'phone!
Where are you from? An apostrophe before 'phone' to indicate that it is a shortened word is definitely not used in America (we just say phone) anymore, so I imagine this isn't the norm everywhere? Phone without the apostrophe was accepted for this one.
If telephone is accepted, then almost by definition 'phone (with apostrophe) should be accepted - though I'd have to agree with the essence of the Sussex Uni argument.
I'd also be tempted to say that if you can bring yourself to write Sussex uni.... shall we say the argument for punctuation of phone is weakened ;-)