You might say that one reason why Barack Obama is president of the US is that he knows how to give a good speech. Since 2004, Obama has written and delivered thousands of speeches. These are usually praised for two reasons: he treats the audiences like intelligent  adults, and he is able to express _ ideas in an easy, natural way. Before becoming president, Obama was a lawyer, a college professor, and a successful writer---his two memories have become best-sellers. What's more, he has some secret weapons. Teleprompter: Obama doesn't go anywhere without his Teleprompter. The textbook-sized panes of glass holding the president's prepared remarks follow him wherever he goes to speak. Writing team: Obama has a team of people who write his speeches. The writers chat with Obama for hours about what he wants to say. They listen to recordings of past presidential speeches and seek advice from advisers. Obama usually edits and rewrites the drafts several times. Tricks for lighthearted speeches: Make fun of the guests: Obama starts his speech by gently teasing his guests. His opening lines draw the audience's attention while giving them an opportunity to relax and laugh at themselves and each other. Make fun of yourself: A good rule for speechmakers: If you're going to make a joke about someone else, be sure to make one about yourself, too. Obama mocks  his own poor choices for filling the position of Commerce Secretary, saying, "No president in history has ever named three Commerce Secretaries this quickly." In fact, his first two nominees for the position withdrew  their names for different reasons. In a process that had otherwise gone smoothly, the Obama Administration found it hard to deal with the problem of filling the Commerce seat. From the passage, we know that Obama's secret weapons are all these EXCEPT   _  .
a writing team a teleprompter humor motivation