Translation:China is very far from the United States.
Tro and tre look similar but they have a bit different meanings. You shouldn't mix them up any more after seeing this:
trO = tOo
trE = vEry
Oh, I remembered seeing in many previous posts people complain how similar tro and tre are. These two words are of course from French where they are pronounced in the same way as in Esperanto (FR: trop, très, respectively). ;-)
Sometimes you can't translate "word by word", so you have to learn small phrases as well:
malproksima de = far from
I think English is the awkward one here, because in many other languages the word for "of" is used instead, similar as in Esperanto.
But "de" in Esperanto means possession, it is weird to use it when talking about distance. In Russian, we have a preposition to talk about distance, "от" (далеко от = far from), but in other cases from = из, (came from = прибыл из). For "of" (de/da) we just use genitive case without preposition (glass of water = стакан воды), but it is also never applied to distance
Why must there be a "the" in the answer when there is no "la" in the original
Because "the United States" is the name of the country. :) You can also use "America" instead (without "the").
lemux-one meant 'for' in Esperanto, which generally translates a 'away' in English. I would like to know the same - is 'for' the same as 'malproksima'?
I'm not sure if I'm right, but according to an online Esperanto dictionary I've consulted, "for" means "away", but not necessarily "far away". I found this given example very helpful to understand what "for" implies: "Marta staris jam kelke da paŝoj for de ŝi".
"Fora", on the other hand, means "far away", but it seems to be an adjective that needs to be followed by a noun, so I'm not sure if it could replace "malproksima" here in this sentence.
Here's a screenshot: