unaccompanied –adj. without another person; alone

guardian –n. someone who takes care of another person or of another person's property

option –n. the ability to choose between two or more things

expensive – adj. costing a lot of money

standard -n. : a level of quality or set of conditions that must be met in order to be accepted

deter-v. to cause (someone) to decide not to do something

impending-adj. happening or likely to happen soon