Where are the vocabulary lists?
I've failed several tests because of surprise words, many with two correct answers. I'd appreciate a list of words to study before the test so we could know which of two equal choices to make when presented with a translation problem in the lessons.
You are just dealing with a computer rather than a human, and you don't get negative scores. Basically you have three options when you are asked for something you can't know: (1) Guess, and just don't worry if it's wrong. (2) Skip, and again don't worry as it's not your fault. (3) Try to find the information elsewhere. Look it up in a dictionary, or google it. That's not cheating. To the contrary, it will give you a much more complete learning experience.
I don't know if this behaviour of the system is intended, but for me it's a feature, not a bug.