Need some help with these questions, thanks!

Which of the following own a portion of the national debt? O All of these are true. O Banks O Foreigners O Federal, state, and local governments O Private U.S. citizens Question 5 10 pts Some cities finance their airports with a departure tax. Every person leaving the city by plane is charged a small fixed dollar amount that is used to help pay for building and running the airport. The departure tax follows the O public-choice principle. benefits-received principle. O ability-to-pay principle. O flat-rate principle. Question 6 10 pts Which of the following statements about crowding out is true? O It is caused by a budget surplus. It affects interest rates and, in turn, consumption and investment spending. O It is not caused by a budget deficit. O It cannot completely offset the multiplier effect of deficit government spending