An easy one to remember, the word has a chain of Os And Rs.
Also, in Spanish "gold" is called oro, so, it's a chain with not one, but two golds.
I typed "long chain" but it marked it wrong and said I needed an "a" in front of it. I thought this article was unnecessary?
Just report it. From the course updates at https://incubator.duolingo.com/courses/sw/en/status:
"We want to encourage the Duolingo community to keep submitting reports on errors on the text exercises. There are instances where articles such as the or a/an are not present in the English translations, for example, so we want to make sure those are there!"