That MGM Grand Youth Center is open to children 3 - 12 years old ________what hotel they are staying in.
本题考查对惯用法的掌握。 四个选项中只有 regardless of是固定用法, 意为“不管,不顾”。 再例如: The law requires equal treatment for all, regardless of race, religion, or sex. (法律要求对一切人平等, 无论其种族、 性别及宗教信仰。 )