R: Air Force One is unique because it has many special features that set it apart from a normal plane.
A: These features are designed to ensure the safety and comfort of the president during flights.
C: According to the author, "This plane has special shields to keep it safe," and it includes "a kitchen that can feed up to 100 people," as well as "a bedroom and bathroom for the president."
E: The special shields are crucial for protecting the president in the event of a threat, and the ability to feed many people indicates that the plane can accommodate large groups, which is important for meetings and traveling with staff. The bedroom and bathroom ensure that the president has private facilities during travel, making it more comfortable and functional for long trips.
S: In summary, Air Force One is unique due to its safety features, facilities for large groups, and private accommodations, all of which make it an exceptional aircraft tailored for the needs of America's president.