Bill and Melinda Gates released their 10th annual letter today. In it they address the "10 toughest" questions they are asked. You can read the entire thing, but here's a list of the questions they answer, which range from topics like education to politics and climate change:

• Why don't you give more in the United States?
  
• What do you have to show for the billions you've spent on US education?
  
• Why don't you give money to fight climate change?
  
• Are you imposing your values on other cultures?
  
• Does saving kids' lives lead to overpopulation?
  
• How are President Trump's policies affecting your foundation's work?
  
• Why do you work with corporations?
  
• Is it fair that you have so much influence?
  
• What happens when the two of you disagree?
  
• Why are you really giving your money away — what's in it for you?