A prefix is a series of letters, or a word, that is added to the  beginning of a word and changes the meaning. For example, in the  word midnight, mid is the prefix.
The more vigorous an activity, however, the more calories youâll burn. Changes in body weight are related to both the duration and intensity of play. Playing singles tennis at average intensity expends 300-600 kcal/h, while high intensity tennis training expends 450-900 kcal/h. Diabetes. The incidence of diabetes worldwide of persons aged 20 or above in 1995 was 4% (approx. 135 million), a figure that will increase to approx. 5.4% (300 million people) by 2025.
The Battle of the Sexes were three notable tennis matches between a man and a woman. The first match was between Bobby Riggs and Margaret Court, over the best of three sets. The second was a nationally televised match between Riggs and Billie Jean King, over the best of five sets. The final match was between Jimmy Connors and Martina Navratilova, over the best of three sets and hybrid rules favoring the female player, dubbed The Battle of Champions.