WK doesn’t automatically tell you what the right answer is when you get something wrong. You have to click a button to open the item details, so just don’t click it.
If you can really use it to your benefit and not fool yourself, it’s probably wise to install the Override Script:
It adds a button to ignore wrong answers. Pretty neat when you answer “slope” instead of “slide” and stuff like that (as far as I’m concerned, they’re the same thing and worthy of ignoring).