The scene I envisioned was a team of doctors looking at chest x rays and deciding which were normal or not.
Or even a medical school, I suppose. I suffer from a limited imagination, apparently.
Medical school there's a good idea. I think my imagination has been honed trying to think up ways to explain some of these rather wacky sentences. Someone has made a post with odd sentences from all over Duo. I can't remember what it's called.
You may be thinking of the Twitter account "❤❤❤❤ Duo Says." Mostly from the Spanish and English programs. It needs more Greek, Hebrew, Welsh, etc.
Well yes but I was reluctant to use the language. You may want to edit it to "S**t ". :-D
You mean 'το', the article?
Because στήθος is a neuter word. Not all words ending in -ς (or specifically in -ος) are masculine. There are feminine adjectives ending in -ης, neuter adjectives ending in -ες and feminine or neuter nouns ending in -ος. Check out this page http://www.foundalis.com/lan/grknouns.htm