Final answer:
The words or phrases that ought to be emphasized to communicate the persuasive tone of the passage are 'I don't think' and 'fastest man on no legs.'
Step-by-step explanation:
The words or phrases that ought to be emphasized to communicate the persuasive tone of the passage are 'I don't think' and 'fastest man on no legs.' These words and phrases highlight the author's personal opinion and the pride they have for Masazumi Soejima's racing abilities despite his physical condition. By emphasizing these words and phrases, the author is trying to persuade the reader to view Soejima's racing on a separate track as a remarkable achievement rather than an insult.