Translation:December is the last month of the year.
how do some people become mods?
Generally, when the current team decides they need another member or two, they have a look at whom they have seen around the forums providing helpful comments, speak to them to see whether they are willing, and then ask staff to make that person a forum moderator.
It's because in the sentence we have: 'im Jahr' = 'in dem Jahr' and 'dem' is a definite article as well as 'the' in English. Whenever in the sentence there are articles like 'der, die, das' and their variants (dem, den etc.) you translate it as 'the' in English but when it's indefinite article like 'ein, eine, einer' and so on you translate it as 'a / an'.
I have reported problems with sound but I believe it requires an extra explanation. When there are scattered words in German that one needs to put in the order to make a sentence, the word Monat in the male version is read in a strange way. It sounds more like "monet". The sound is ok in both fast and slow speech as well as in the female voice only male for a single word is causing this problem. Of course this is just one of many exercises where the problem exists.