Stuck with Food/Animals
I'm currently stuck with Food/Animals - it seems that there are too few lessons and available translations to reach the required score. It's a little frustrating, so I wonder how long it'll take until new translations would become available?
If you get stuck with not enough points to complete the lesson, look at the Translations menu and pick something. If you watch carefully where the scores are going, some of them add to your lessons, not just skill points. I've "mastered" quite a few lessons just by doing some random translations.