This quiz does not actually work -- cannot click around, yellow boxes don't follow the rounds. I stopped after 2 1/2 minutes of trying. Also, I suspect the time isn't long enough.
3 minutes of time and type-ins added: this was easy thanks to the 'recommended type-in' option which Jerry pointed out to me! Unfortunately the yellow boxes problem is unfixable, I was planning to make similar quizzes but don't think I will if this doesn't get fixed :(
As you say the clicking isn't easy either, however if you click in the middle of a cell you should be able to highlight it.
thanks for your comment