Tests are regularly conducted in this area to ascertain whether pollution levels have dropped.

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions.

William Worral Mayo provided crucial assistance to his sons in launching their team practice in 1889, while they were holding positions at t. Mary’s hospital. William James became recognized for his surgical skill in gallstone, cancer, and abdominal operations. He and his brother, Charles Horace, founded the Mayo Graduate School of Medicine and donated $1.5 million to establish the foundation for contributions. Charles William, the son of Charles Horace Mayo, became a member of the board of governors at the Mayo Graduate School and an alternate delegate to the United Nations General Assembly before retiring from the clinic in 1963. William James Mayo presided in the American Medical Association and served in Army military corps as a brigadier general in the medical reserve. Charles Horace was a professor of surgery and a health officer of Rochester subsequent to serving in the armed forces between 1914 and 1918. The Mayo practice became known far and wide for its success in surgical procedures. In 1914, the practice moved into its own medical center, and today the number of patients equals approximately 280,000 per annum. Since the clinic opened in 1907, 4.5 million patients have been treated.