"The boy asks and the girl answers."
Translation:Pojken frågar och flickan svarar.
"Be" is used if you're asking someone to do something or if you're asking them for a favour.
The words frågar and svarar haven't been taught before, I think, so if it's a mistake and anyone can fix this you're more than welcome to do so :)
They're taught where this sentence is, in the Questions skill.
Sometimes sentences are shown in the wrong place, but unfortunately that's a global bug that we as course contributors cannot fix.