What should you do once left alone?once是这句话的什么成分啊?

What should you do? Do what you should what should you do then? what should you do （ ） do should what you then . WHAT SHOULD YOU DO THEN What should you do then? only do what you should Do you what they should do? do what you should do怎样翻译 Do you think what should I do 还是Do you think what I should do Focus on what you should do then what do you should 连起来 What should you do in learning English? What do you think education should be? what should I do for you 是you need do what you should do 还是you need to do what you should do? What you should/should not do for listening skill?