user: Question: On April 18, which team was the visitor?
Columns: ['Date', 'Visitor', 'Score', 'Home', 'Leading scorer', 'Attendance', 'Record']
Types: ['text', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['April 2', 'Denver', '104-101', 'Cleveland', 'Mark Price , 21 points', 'Gund Arena 20,562', '39-32']
SQL:

assistant: SELECT "Visitor" FROM "Table" WHERE "Date" = 'April 18';