Translation:The merchants carry the food and sell it in the forum.
That is not a good translation.
Foods is a special word in English. When you use it in the singular, and in the plural, the meaning change.
That is not the case in Latin, where this noun is not an uncountable.
Cibos (plural), in general, in Latin, means "dishes". (It can also refer to "food" in general I think, according to Latin sentences I've found)
But it's never like "foods" in English, like "fishes" is not like "pisces".
It's normal that there is no "it" in the wordbank, because there's not word to translate it in the Latin sentence!
But it's normal that you include it, to make the English sentence sounds correct.
The "it" results of the particular structure of the Latin sentence.
"Mercatores cibos portant et in foro vendunt."
Mercatores cibos portant = The merchants carry the food/dishes
et in foro vendunt.
That's perfectly correct in Latin, but a word by word translation in English would give "and they sell in the market/forum".
That is not a correct grammar sentence in English, you need to add the "it".
Very interesting sentence to see how Latin reuse something that has already been said, without using a pronoun complement (like "it"),
as the "it" is obvious, we don't use it in Latin, but English grammar needs it.
Actually, I'm not. In my case I'm more taking into account the fact that "cibo" in Italian behaves exactly like the English word "food" does. So why are you so sure of the fact that that's not the case in Latin? Can you provide examples in the literature? I've checked different Latin dictionaries and they hardly give examples where cibus appears in plural form.
There is a scope of plural problem. The sense seems to me to be that the sentence is the plural version of: Mercator cibum portat et in foro vendit. Each merchant brings his/her food to the market and sells it. It does seem odd to say Mercatores cibum portant et in foro vendunt, making it sound like a joint venture. (All the merchants jointly bring the food and sell it.) The best way to make the sense clear in English is to use a possessive. The merchants bring their foods to the market and sell them. But that's probably not feasible to license as an answer.
The difference is subtle, but it exists.
The merchants carry the food. It can be a long distance or short one, but is a first action. And it's not done inside the market, only to the market. And it is done well before the selling.
Then, AFTER the carrying is over, they sell in the market.
Both carrying and selling are not being done in the market.
So in the english translation, you have to reflect that same transition that is communicated in the Latin.