Tennis is a racket sport that is played either individually against a single opponent (singles) or between two teams of two players each (doubles). Each player uses a tennis racket that is strung with cord to strike a hollow rubber ball covered with felt over or around a net and into the opponent’s court. The object of the game is to manoeuvre the ball in such a way that the opponent is not able to play a valid return.
The player who is unable to return the ball validly will not gain a point, while the opposite player will.[1][2] Tennis is an Olympic sport and is played at all levels of society and at all ages. The sport can be played by anyone who can hold a racket, including wheelchair users. The original forms of tennis developed in France during the late Middle Ages.[3] The modern form of tennis originated in Birmingham, England, in the late 19th century as lawn tennis.[4] It had close connections both to various field (lawn) games such as croquet and bowls as well as to the older racket sport today called real tennis.[5] (來源 )
