In this Tuesday, March 10, 2015 photo, rime ice covers rocks on the summit of Mount Washington in New Hampshire. Rime ice occurs when freezing fog hits stationary objects in frigid conditions. (Photo by Robert F. Bukaty/AP Photo)

Classic antique cars are seen at an auto dealer in West Branch, Iowa, March 6, 2015. Iowa, the American heartland. Endless farm fields and quiet towns. 56,273 square miles that are soon to become the focus of the nation as the long process of electing the next U.S. president begins. (Photo by Jim Young/Reuters)

A model (C) looks at her mobile phone while backstage before the araisara Sara Arai Collection show during China Fashion Week in Beijing on March 27, 2015. China Fashion Week runs from March 24 to March 31. (Photo by Wang Zhao/AFP Photo)

Maharashtrian women dressed in traditional costumes attend celebrations to mark the Gudi Padwa festival in Mumbai March 21, 2015. The festival marks the beginning of the new year for Maharashtrians and is celebrated widely in Maharashtra and in the Konkan region. (Photo by Danish Siddiqui/Reuters)

A Pakistani scavenger girl writes on a notebook she collected from a garbage, while another girl sits next to her in Lahore, Pakistan, Wednesday, April 1, 2015. Thousands of children pick recyclable items from waste dumping points to earn living for their poor families. (Photo by K. M. Chaudary/AP Photo)

Indian Muslim devotees travel in an auto rickshaw during the Urs festival in Ajmer, India, Thursday, April 23, 2015. Thousands of devotees from different parts of India travel to the shrine of Sufi saint Khwaja Moinuddin Chisht for the annual festival marking the saint's death anniversary. (Photo by Deepak Sharma/AP Photo)

In this March 18, 2015 photo, a boy rides a mechanical bull for children at the Texcoco Fair on the outskirts of Mexico City. In Mexico, these types of fairs date back to Spanish colonial times, and in some smaller communities they are organized around the feast days of Roman Catholic saints. (Photo by Eduardo Verdugo/AP Photo)

A firefighter uses a saw to open a metal gate while fighting a fire in a convenience store and residence during clashes after the funeral of Freddie Gray in Baltimore, Maryland in the early morning hours of April 28, 2015. (Photo by Eric Thayer/Reuters)