I got the impression that "Jeruk dan apel" could also mean "an orange and an apple" since there didn't seem to be an indefinite article in other examples, but that was marked wrong and it suggested "orange and apple" instead.
I put "orange and apple", the direct translation. The correct answer was "Oranges and apples", shouldn't that be "jeruk-jeruk dan apel-apel"? I can understand if the solution was "an orange and an apple", but really, we're here to learn Indonesian, not to have our English corrected.
"Jeruk dan apel" is all singular words, why does Duolingo teach it to be plural, the plural form is "jeruk-jeruk dan apel-apel".
Anda benar, jeruk dan apel adalah kata tunggal. Seharusnya bukan oranges tetapi yang benar orange.