To me, it sounds odd- we are going to sell THE shoes. I think it sounds more natural to say we are going to sell shoes, unless a group of people are all going to sell one specific set of shoes.
Many Duo sentences sound odd, often because there is no context. But if we were working with paragraphs we'd likely never get through one without losing a heart. ;) "We'll sell the shoes, but those socks will never move." Presence/absence of articles is confusing. Thankfully, native speakers I have encountered in "real life" are very understanding. Sometimes when I ask if it should be "queso" or "el queso" the answer is a shrug of the shoulders, a smile, and a "whatever."
"We are going to sell the shoes, the ones that we've been holding onto for decades in the hopes that they'd become stylish again."
Duolingo doesn't seem to be consistent with whether the article should be used or not in translation.
It seems appropriate that "vender" not only translates as "to sell" but also as "to sell out" and as "to betray." I think a number of English speakers could relate to those alternative meanings all too well, just as well as the Spanish.
This a bizarre sentence. It seems to many of the sentences are bizarre, and no one would ever use them.
Leon, I double-checked <SpanishDict> (which is freely downloadable): Nosotros vamos a vender esos zapatos.
To me "we are going to sell shoes" sounds more natural, but I knew duolingo would want "the shoes". I was right.