"Jams or pieces of chewing gum?"
Translation:ריבות או מסטיקים?
This is a result of:
(1) the short-sighted refusal to accept the phrase "jams or chewing gums" as a translation for the Hebrew sentence that here is given as the answer; and
(2) using the alternate translation for the Hebrew sentence as the original English sentence in this exercise.
The controversy arises from demands that each noun - "jam" and "chewing gum" - cannot be used in a plural form. While their plurals are uncommon, they are not ungrammatical when used properly.
Well, as answers are added manually, there won't be ever real equity in Duolingo, if you see it as a game to win. I suppose several portioned pieces of chewing gums would be חֲתִיכוֹת שֶׁל מַסְטִיקִים. The idea of חֵ֫לֶק is more of breaking up something to smaller fragments, so חֲלָקוֹת שֶׁל מַסְטִיקִים sounds to me more like a gum has crumbled to smaller pieces. I suppose the akward translation of the original sentence is due to the lacking of a plural of chewing gum in English, because most see it as an uncountable noun, and chewing gums might be several brands of chewing gum.