This progression of sentences is amusing. I'm picturing a pater talking to his kids telling thrm why they need to be seated, giving examples: "even a drunk parrit can sit! Why not you kids!?" Haha :)
It seems odd that the word "parrot" has come up so much, but we haven't learned the word for "bird" or "eagle" or "owl" yet.
actually, duolingo teaches rather the grammar and common usage by giving so many likewise structured sentences. vocabulary has secondary importance. and it's a good way to learn a language, in my opinion. one can learn these birds from any online or printed dictionary, but it's hard to show the usage and grammar. drunk parrots are funny and it makes your mind to remember the lesson anywise.