Question : DB Desing tips

I am desining some db for application that uses testing as a part of it and stores questions answers tables into db (sql).
the desing is like this:

Test
  testID
  testName
  ...

Question
  QuestionID (PK)
  testID (FK to test)
  QuestionText
  correctAnswer bit
  ...

Answer
  AnswerID (PK)
  QusetionID (FK to Question)
  AnswerText
  AnswerResult
  ...

userAnswer
  UserID (FK to User)
  AnswerID (FK to Answer)
 ...

now I need more than one type of questions, True/False, check boxes, and multiple chocies
what is best way to handle that?  

Answer : DB Desing tips

See similar designs that might help:

http://wilma.vub.ac.be/~se4/papers/ddd.html#tth_sEc2.4

http://www.bigresource.com/MS_ACCESS-Table-design-for-Survey-Response-Database-QDD4wP85.html#A32Fj3cK

http://www.codingforums.com/archive/index.php/t-16220.html

Also go throguh the links in: http://drupal.org/node/73607