user: Question: Which class was on the Las Vegas Motor Speedway for 2 Hours?
Columns: ['Race', 'Length', 'Class', 'Circuit', 'Date']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['Rolex 24 at Daytona', '24 Hours', 'Both', 'Daytona International Speedway', 'February 1 February 2']
SQL:

assistant: SELECT "Class" FROM "Table" WHERE "Length" = '2 Hours' AND "Circuit" = 'Las Vegas Motor Speedway';