1money does not buy happiness or security. 2john ringling, one of the five ringling brothers of the ringling brothers circus, started out in 1884 with a trained horse and a performing bear. 3for over forty years, he worked hard at the family enterprise, bought up smaller circuses, and imported new acts. 4in the 1920s, he was rated as one of the world's wealthiest men and owned every sizable circus in the country. 5over 5,000 people were on his payroll, and over 240 railroad cars were in his retinue each time the circus moved. 6at the time of his death, however, he was a nervous, unhappy man; he was also bankrupt and beset by lawsuits. 7his carefully built circus empire passed into alien hands.8all those years of work had turned to dust. what is the topic sentence?

answer: i would say he was very determined and persistent in overcoming obstacles.

explanation:   "the magician of menlo park" as he was called, liked to tell an incident that happened when he was 8 years old and came back home crying after attending school for three months because his teacher called him "sterile and unproductive". from nowadays perspective, we can say that thomas alva edison was one of the most persistent and determined man that has ever existed. when edison was 14, he contracted scarlet fever. the effect of the fever, as well as a blow to the head by an angry train conductor, caused edison to become completely deaf in his left ear, and 80-percent deaf in the other. so as you can see he had to struggle to not so many minor issues but he always succeeded.