Query the list of CITY names starting with vowels (i.e., a, e, i, o, or u) from STATION. Your result cannot contain duplicates.

This question seems to be asking for a SQL query. Here's how you can do it:

SELECT DISTINCT CITY 
FROM STATION 
WHERE LOWER(SUBSTR(CITY, 1, 1)) IN ('a', 'e', 'i', 'o', 'u');

Here's the step by step explanation:

1. SELECT DISTINCT CITY: This part of the query will select all unique city names from the table. The DISTINCT keyword ensures that there are no duplicate city names in the result.

2. FROM STATION: This part of the query specifies the table that we are selecting data from, which is the STATION table in this case.

3. WHERE LOWER(SUBSTR(CITY, 1, 1)) IN ('a', 'e', 'i', 'o', 'u'): This is the condition for selecting the data. The SUBSTR(CITY, 1, 1) function gets the first character of the city name, LOWER function ensures that the comparison is case-insensitive, and IN ('a', 'e', 'i', 'o', 'u') checks if the first character is a vowel.