generate questions: Southern California is also home to the Port of Los Angeles, the United States' busiest commercial port; the adjacent Port of Long Beach, the United States' second busiest container port; and the Port of San Diego.
What is the United States busiest commercial port? {sep_token} What is the second busiest container port in the United States? {sep_token} The Port of Long Beach belongs to which region of California? {sep_token}