VOA慢速英语:US Downgrades Thai Air Safety

tourism – n. the business of providing hotels, restaurants, entertainment, etc., for people who are traveling

aviation – n. the business or practice of flying airplanes, helicopters, etc.

category – n. a group of people or things that are similar in some way

expertise – n. special skill or knowledge: the skill or knowledge an expert has

destination – n. a place to which a person is going or something is being sent​