index = 0
json.status 3
# st: 0 实践题 1 选择题
if @challenge.st == 0
  json.message do
    json.array! @challenge_answers do |answer|
      index += 1
      json.answer_id answer.id
      json.answer_name answer.name
      json.answer_score answer.score
      # 高层级不给答案
      if @power || @game.answer_open >= index
        json.answer_contents answer.contents
      end
    end
  end
else
  json.message do
    json.array! @challenge_answers do |answer|
      json.position answer[:postion]
      json.answer_contents answer[:answer]
    end
  end
end