Potatoes are cockroaches.
My first thought was that this is a weird thing to say, and so I wondered where this came from - an idiom or colloquialism perhaps, or some cultural reference?
So I went over to Tatoeba to find out, and followed the history …
In the beginning there was a Chinese sentence which was translated as “Potatoes are cheap”.
This was eventually translated into Portuguese as “As batatas são baratas”, where “barato” is the Portuguese word for cheap (and in this case shows up as the feminine plural form “batatas”).
Now, the Portuguese word for cockroach is “barata”, so someone decided to translate this into English as “Potatoes are cockroaches” and similarly the Spanish form “Las patatas son cucarachas”. These were then subsequently translated into other languages.
And hence, we have this pair of sentences that don’t appear to have any real significance (in the potatoes = cockroaches sense), in any language whatsoever - it’s just a potential word play in Portuguese that has been translated into each of these languages.
Whilst I don’t see this as a problem on Clozemaster for this pair of sentences (at least for me) as the two sentences match, it would cause a problem if some language version of “Potatoes are cheap” and another language version of “Potatoes are cockroaches” were combined. As the translations-of-translations on Tatoeba include both sentences this is a highly probable eventuality.
I noted in passing that on this page of a French sentence meaning “Potatoes are cheap” @morbrorper had posted that the English “Potatoes are cockroaches” should be removed, so maybe there’s already at least one version of this bad combination sitting somewhere on Clozemaster.