"The dolphins eat small fish."
Translation:Delfinii mănâncă pești mici.
Yes, I think the understanding of the two sentences is correct but when the example sentence from the lesson is 'Delfinii mănâncă pești mici' means 'The dolphins eat small fish', then should the alternative sentence 'Delfinii mănâncă peștii mici' be marked as an incorrect choice? I chose just the one sentence and it marked me wrong as it said that 'Delfinii mănâncă peștii mici' should had also been chosen as well.
For all non-English people present, there is no such word as "Fishes" as a plural in the English language. It is occasionally used to describe someone performing a leisure activity as in "he fishes off the pier" but as regards the fish itself. fish is plural as well as singular for example "there are plenty of fish in the sea" ;)