Final answer:
The correctly punctuated parts in the passage are the sentence regarding America's economy and spirit in parentheses and the one with a colon introducing two related questions regarding seat belt usage among different age groups.
Step-by-step explanation:
In assessing the punctuated sections of the passage, two parts are punctuated correctly. The sentence 'What will happen to America’s economy (and its spirit) when high schoolers can no longer work the fast-food jobs and restaurant hostess positions?' uses parentheses correctly to add an incidental remark. Additionally, the question 'But let me ask you this: Do people under the age of 21 really wear their seat belts less often than older people, or are they just caught more often?' is correctly punctuated with a colon introducing a list of related items in the form of two related questions.