Multiple-Choice Questions with More than One Right Answer, or No Right Answers.
To make the multiple-choice questions more effective for learning, and more fun, I think there should sometimes be more than one correct translation available.
And, perhaps, there should sometimes be no correct translation, where you would check none then continue to answer correctly.
There are questions with two or even three correct answers. Personally, I find them frustrating because one of the options is often kind of marginal, and the learner has to guess if it is accepted or not.