user: Question: What is the name of the national final main host at BBC Television Centre, and the selection show was Eurovision: Your Country Needs You?
Columns: ['Year(s)', 'Selection show', 'Venue', 'National final main host', 'National final co host', 'Semi final/heat host']
Types: ['text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['1956', 'UK did not participate', 'UK did not participate', 'UK did not participate', 'UK did not participate', 'UK did not participate']
SQL:

assistant: SELECT "National final main host" FROM "Table" WHERE "Venue" = 'BBC Television Centre' AND "Selection show" = 'Eurovision: Your Country Needs You';