(CNN) -- Jo-Wilfried Tsonga ended Roger Federer's hopes of winning a record-equaling seventh Wimbledon title on Wednesday as the French 12th seed staged a stunning fightback to reach the semifinals. Federer appeared to be cruising into the last four after winning the first two sets, but Tsonga inflicted the Swiss world No. 3's first defeat from that vantage point in 179 grand slam matches. It was only the third time in the 29-year-old's glittering career that the 16-time grand slam champion had surrendered a two-set lead. Tsonga, ranked 19th in the world, triumphed 3-6 6-7 (3-7) 6-4 6-4 6-4 on Centre Court, serving out to love as he earned a clash with second seed Novak Djokovic. The Serbian, who beat Tsonga in the 2008 Australian Open final, ended the dream run of Australian 18-year-old Bernard Tomic. Tsonga defeated Federer for just the second time in six meetings, their first on grass. "It was amazing. I played unbelievable. It's never easy to come back against Roger. I'm so happy, it's crazy," the 26-year-old told reporters after reaching the semifinals at Wimbledon for the first time. "He's the biggest champion in the sport. He has achieved so much and is the best player in the world. To be two sets down and come back was unbelievable. I served really well. Against Djokovic I will have to come out and do the same again." Federer has now lost in the quarterfinals two years in a row, being beaten by eventual runner-up Tomas Berdych in 2010. "Jo played great. Really from start to finish I don't remember seeing a break point after I broke him in the first game," Federer said.

Question: "Who was the tennis player that lost to Jo-Wilfried Tsonga?"

Response: "Federer"
OPTIONS:
- no
- yes

A: yes

Problem: There once was a guy named Kevin and girl named Erin. They really liked spending time together. One day, Kevin traveled from his home in the United States of America to Erin's house in England. They then thought to take a sudden trip around the world. They first traveled by plane around Europe, where they saw many different people and sights. They then took a boat to Africa and Asia, where they went on a trip through the mountains. Later in the month, they traveled to China by train and were allowed to see how different life was over there. Next they took another plane to Australia, where they had a lot of fun seeing kangaroos and a different type of English speaking people. After spending a week in Australia, Kevin and Erin took a really long plane ride to North America, where they drove across the land. They saw everything from the mountains to forests. They even got to visit the beach! Because they had so much fun, Kevin returned home with Erin to England where they hung out and spent the next few days and months talking about all of the neat things they saw and did on their trip.

Question: "Who flew in a plane with Erin?"

Answer: "Kevin"

OPTIONS:
- no
- yes
Answer: yes

Question:
PHOTOGRAPH COLLECTING gains new stature as prices rise. Price records are being set at auctions this week. At Christie's, a folio of 21 prints from Alfred Stieglitz's "Equivalents" series sold for $396,000, a single-lot record. Other works also have been exceeding price estimates. In part, prices reflect development of a market structure based on such variables as the number of prints. This information used to be poorly documented and largely anecdotal, says Beth Gates-Warren of Sotheby's. "There is finally some sort of sense in the market," she says. Corporations and museums are among the serious buyers, giving greater market stability, says Robert Persky of the Photograph Collector. "When I see prints going into the hands of institutions, I know they aren't going to come back on the market." Most in demand: classic photographs by masters such as Stieglitz and Man Ray. But much contemporary work is also fetching "a great deal of money," says Miles Barth of the International Center of Photography. After reading the above, is "35" the correct answer to the question "How many of Alfred Stieglitz's prints sold at a record price?"? OPTIONS:
- no
- yes

Answer:
no

Input: Nathan read the package of words in silence, his only motions the steady progress of his eyes and occasional replacement of pages. Allan sat nervously across from him in a chair Nathan had probably upholstered himself, a patchwork design of fabric containing easily more stuffing than any other furniture item of the period. At long last, Nathan reached the end and set down his reading on the table between them. Allan leaned forward unconsciously. "It's the best story you've ever written." Allan exhaled and leaned back into the chair, his face relaxing in imitation of his thoughts. "So," he asked, "you don't think it's a waste of ink and paper, a futile expedition into morbidity or literary debauchery?" "Heavens, no," said Nathan, aghast. "This is one of the strongest works I've read in ages. It speaks to the deepest storyteller's instinct within us all, yet is entirely original. My dear friend, you have done it. Oh, they may rail against you at first; they may decry you as a heathen or a literary savage; but while those in power say such things, others will read your tales and see their true worth. Believe me when I say that you will be read a century from now." Allan, though dubious as to that possibility, felt some temptation from the compliment; mainly, it granted him the encouragement he still needed. Nathan promised to show the story to a printer he knew and Allan left it with him, then walked home under the spreading maples with a smile lingering on his face. He felt now that perhaps Nathan was right; although the man was somewhat peculiar, he had both an unimpeachable honesty and a certain propensity for insight. Certainly, it was undeniable that the stories had an originality to them. His mind's strangest fruit had ripened at last, and he found the taste less bitter than expected. These thoughts and others like them filled his head as he walked the long road home. It was evening, and the sky burned orange in the west when he neared home at last.

Does the response "He was worried that Nathan would not like what he wrote" correctly answer the question "Why was Allan nervous?"?

OPTIONS:
- no
- yes
***
Output:
no