Critical thinking quizzes are usually rubbish. In fact in some countries even the material provided by exam boards are rubbish. And I’m saying this not without sympathy. One only needs to watch a single episode of Family Guy, The Revolution will be Televised or Brasseye to be reminded that though errors in reasoning can be hilarious, they are not always clearly a clear case of one error. Of course occasionally they are (“it’s not a drug it’s a drink” etc), but more often one could make a case that a number of mistakes have been made (eg. Peter Griffon’s incredible ‘Mark Harmon’ speech).
Routledge’s companion website for Tracy Bowell and Gary Kemp’s Critical Thinking: A Concise Guide is not like this. It is clear. It is constructive and it is helpful. I haven’t yet managed to read my inspection copy, but if it is as clear as this site I will be adopting it right away. You can find it here: Critical Thinking: A Concise Guide.