The translation for “I’m very thirsty” is “tengo mucha sed” which is right but the literal translation below says “estás tú sediento?”, that’s wrong because that means “are you thirsty?”
It seems there is no forum thread for the course, even though it is an official Memrise course. The only course forum thread I can find is the one for UK-English which can be found here:
@MemriseSupport, @angileptol: isn’t there a course forum dedicated for US-english for Spanish speakers? This course here:
I don’t see that word in level 5 but that is not wrong. Those are two of many possible translations for llevar. The most common translation being “to take/ to carry/ to wear”. Also “to spend time/ to lead”.