Translation:My sister is putting food into the fridge.
Well, both are accepted, "the" is the default answer.
The word "suma" is taught in the "Numbers" skill, lesson 2 - it has three sentences. It happens sometimes though that I strengthen a skill and I suddenly learn a new word which I was supposed to learn earlier, so maybe this is such a situation.
thank you again and again for your help I actually live in Poland and I really need to learn this amazing language but it has been very hard because (polish) slavik is very different from (portuguese) latin so I find very little similarities between the two languages but I believe that one day I will be able to say "mówię po polsku" instead of "nie mówię dużo po polsku" :)