Jin,
There is a flash cards plugin that may be a way to go. The answer is on the back of an animated cars
You need to somehow set a toggle for the answer, and if the correct answer is given conditionally display the result.
otherwise if you just want to conceal the answer you could do so with the details widget, the user click to see the answer.
With computer based Q&A multiple choice can be better simply because determining a textual answer is correct can be complex.
others have used tiddlywiki this way so a bit of a search for "tiddlywiki" +quiz and other related keywords should help you find previous work.
Presentation or slides may be other keywords.
Tones