The phrase "are utterly dependent on" is correct and usable in written English.
You can use it to express a strong reliance on something or someone.
Example: "Many species are utterly dependent on their natural habitats for survival."
Alternatives: "are completely reliant on" or "are entirely dependent on".
FACE it: many business travellers are utterly dependent on their smartphones.
Far more people are utterly dependent on it than on any other food plant, although it is not exceptionally nutritious.
If this tournament proved anything it is that Brazil are utterly dependent on Neymar and that he is uncomfortable – as anyone would be – with the pressure.
"Outside of New York, people are utterly dependent on cars to get anywhere at all," Eric Drooker, the artist behind this week's cover, "Fifty-ninth Street Bridge," says.
In Missing Out: In Praise of the Unlived Life, he expands the idea, writing: "There is nothing we could know about ourselves or another that can solve the problem that other people actually exist, and we are utterly dependent on them … There is nothing to know apart from this, and everything else we know, or claim to know, or are supposed to know, or not know, follows on from this".
Quite apart from the fact that new-born babies are utterly dependent on others, and no more capable of independent life than they were immediately before being born, there is something absurd, as Harris put it, in supposing that something crucial happens in the birth canal, so that at one end the foetus has no right to life, and when it emerges at the other, it has.
Santorum was utterly dependent on super PACs to remain in the race, yet he soldiered on.
All those individuals are or were utterly dependent on the other.
Romney, on the other hand, is utterly dependent on winning Florida and North Carolina, two traditionally Republican states that are now tossups.
