About a year ago,if you had asked who Dinara Safina was,the answer would have been,"She is Marat Safin's younger sister." She was overshadowed by her wonder brother.But now she has made a name for herself:the world No.1 player in women's tennis. The 22yearold Russian overtook Serena Williams of the US for top ranking on April 20."Before,every place I go,I am Marat's sister.Nothing else,"she told New York Times."I always wanted to be myself,and now finally the results come,and people can know me as Dinara Safina." Safina has made it to two great event finals,in the 2008 French and in the 2009 Australian Open,and won a silver medal in the Beijing Olympic Games. Clearly,family isn't the only connection Safina and her brother share.Their DNA burns with competitive fire.Safin has held the distinction for years of being a hottempered player on court.When he lost his temper,he would smash a racket  .Safina is as emotionally explosive as her brother.A headline in the newspaper The Australian once described her as "mad as a snake".The Sydney Morning Herald,during the Australian Open,summed up Safina's volatile   emotional state with the headline--Safina goes from basket case to top of the world. It's not rare for a family to have two top tennis players.Safina's father owns a tennis academy and her mother worked as a coach."I had no choice but to become a tennis player,but I don't mind being a tennis player," Safina said. From this talented family she is also given one of her best weapons on court,her size.She is 1.82 meters tall and weighs 70kg.But it is hard work that led her to her recent success. "I hope to prove to everyone over the coming months that I deserve the honor of being world No.1,"she said. Which one of the following doesn't contribute to Safina's success?
Her hard work and strong competitiveness. Her emotional explosion and volatile emotional state. The fact that she is 1.82 meters tall and weighs 70kg. The fact that her parents are both good tennis players.