Imagine you are standing in a farm field in central Illinois. The land is so flat you can see for miles and miles. On a clear day, you might see a grain silo 20 miles away. You might think to yourself, it sure is flat around here. If you drive one hundred miles to the south, the landscape changes. In southern Illinois, there are rolling hills. Why do you think this is? What could have caused these features? There are no big rivers that may have eroded and deposited this material. The ground is capable of supporting grass and trees, so wind erosion would not explain it. To answer the question, you need to go back 12,000 years. Around 12,000 years ago, a giant ice sheet covered much of the Midwest United States. Springfield, Illinois, was covered by over a mile of ice. Its hard to imagine a mile thick sheet of ice. The massive ice sheet, called a glacier, caused the features on the land you see today. Where did glaciers go? Where can you see them today? Glaciers are masses of flowing ice.

Question: "What's the difference between central and southern Illinois?"

Response: "In central Illinois, he land is so flat you can see for miles and miles.In southern Illinois, there are rolling hills"

A: yes

The Venetian artist Jacopo de' Barbari, whom Durer had met in Venice, visited Nuremberg in 1500, and Durer said that he learned much about the new developments in perspective, anatomy, and proportion from him. De' Barbari was unwilling to explain everything he knew, so Durer began his own studies, which would become a lifelong preoccupation. A series of extant drawings show Durer's experiments in human proportion, leading to the famous engraving of Adam and Eve (1504), which shows his subtlety while using the burin in the texturing of flesh surfaces. This is the only existing engraving signed with his full name. Durer made large numbers of preparatory drawings, especially for his paintings and engravings, and many survive, most famously the Betende Hande (English: Praying Hands, c. 1508 Albertina, Vienna), a study for an apostle in the Heller altarpiece. He also continued to make images in watercolour and bodycolour (usually combined), including a number of still lifes of meadow sections or animals, including his Young Hare (1502) and the Great Piece of Turf (1503, both also Albertina).

Question: "What caused Durer to begin his own studies and experiment with human features in his art work?"

Response: "Jacopo de' Barbari being unwilling to explain everything he knew"

A: yes

(CNN) -- As Iranian President Mahmoud Ahmadinejad visited the U.N. General Assembly in New York last month, the spotlight was once again on Iran. And true to form, the Iranian president made his fair share of provocative statements for the Western media. But while Ahmadinejad's mercurial rants captured our media's attention, back in Iran a coordinated strategy against the women's movement continued. On the eve of Ahmadinejad's arrival to New York, Shiva Nazar Ahari, a prominent young female defender of human rights, received a heavy sentence of six years in prison on charges including the vague crime of "waging war against God" -- a convenient catch-all offense for anyone who criticizes the regime and its human rights record. There's no denying it -- Iran's women have had a bad year. Nazar Ahari joins a steadily increasing number of other women's rights activists who are in prison for no greater crime than their attempt to fight for the rights of the women. Hengameh Shahidi, Alieh Eghdam Doust, Bahareh Hedayat and Mahdiyeh Golrou have all been sent to Tehran's notorious Evin Prison on trumped-up charges related to their activism. And while Nobel Peace Prize laureate Shirin Ebadi, arguably the most internationally recognized Iranian women's rights activist, remains unable to safely return to her country, the government is targeting those affiliated with her for arrest and imprisonment, including her lawyer Nasrin Sotoudeh and her former aide Jinous Sobhani. Since the 2009 disputed elections and associated government crackdown on the overall reform movement, the government has increasingly targeted women activists. The reasons behind this go well beyond the misogynist nature of Iran's religious leadership. Rather, it is more part of a deliberate and calculated strategy of the Iranian authorities to strike at the heart of the regime's greatest vulnerability -- internal legitimacy with its own people. See more CNN.com opinion articles Iran's government recognizes and fears the broader power of the women activists who have been on the front line of reform in Iran for more than a decade. One can roughly draw an analogy between the women's movement in Iran to movements of religious groups in Burma or Tibet, or the labor "solidarity" movements in the former Eastern bloc and associated labor-Roman Catholic solidarity in Poland -- all advocating initially for the freedoms of a specific group but which provoked government fears for their transformative power to promote broader human rights progress. While the outside world occasionally reacts to the most egregious manifestations of Iran's repression of women -- such as the international condemnation associated with Sakineh Mohammadi Ashtiani, an Iranian widow sentenced to stoning on charges of alleged adultery -- these events are often portrayed simply as a consequence of the regime's archaic viewpoint about gender.

Question: "Who came to New York the evening Nazar Ahari was sentenced?"

Response: "Mahmoud Ahmadinejad"

A:
yes