I learned 5 foreign languages different ways, and the one I'm most proficient in, I learned the hardest way, doing grammar excercises, where for every of 31 paragraphs of the manual, I had to articulate ~200 sentences, each from scratch. I abandoned flashcards on the 2nd or 3rd month of learning.

The one I'm worst in is German, where every manual was well elaborated in terms of graphical design, but in every exercise you're asked to insert a word or two. Or pick an answer from a set. Basically, Duolinguo sent to printer. So after couple of years of working with teachers and taking intensive courses, my level is B1..2. I can listen to radio and understand something, I can read something. I actually can speak in a shop -- they'll understand my level and speak accordingly. I couldn't find a teacher that doesn't just drill you through these same fancy books.

So, these tasks, to pick the correct option from a list, are good for testing if the subject is given little enough time. They're terrible at teaching.