what global problems are troubleing and endangering the earth and human beings?

Why do you think global problems matter to Americans and what can Americans do about them? what global problems are troubleing and endangering the earth and human beings? what is global warming? what is global warming? 翻译：what is global warming? sure what problems翻译 global global What problems do you have? What problems can waste bring what do problems training classes What problems are they facing What can we do about global warming? what of the global warnming?怎么翻译 What health problems can junk food cause? What is the student's problems?改错 what problems do college student face today what problems can this difference cause?