The baseline
the area that you serve into is the same as in singles. The server may stand anywhere in between the center mark and the doubles sideline
It's where you stand when you serve. Behind the baseline in one of the four corners of the court. Best way I can say it.
International Tennis Federation.
Wide receiver.
It stands for Women's Tennis Association
Advantage
'Des tennis' are most probably 'des (chaussures de) tennis' which are tennis shoes in English. That could also stand for 'des (terrains de) tennis', which are tennis courts.
Wonderful Talkitive Ponies
International Table Tennis Federation
Lawn Tennis Association
almost all of them. it just depends how good they are that makes tennis stand out in a country