A mother bear takes a dip in the water to cool off in the warm summer sun but refuses to leave her three youngsters behind – so they climb aboard her back. (Photo by Jon Langeland/Solent News & Photo Agency)

An alpaca chewing a leaf is pictured on November 18, 2014 in the zoo of Frankfurt am Main, Germany. (Photo by Frank Rumpenhorst/AFP Photo/DPA)

Gloria Lincoln-Thompson carries her 9mm Smith & Wesson pistol in her waistband during a rally in support of the Michigan Open Carry gun law in Romulus, Michigan, in this April 27, 2014 file photo. (Photo by Rebecca Cook/Reuters)

The lightest material ever made has been produced by a team of scientists in China, a Chinese university announced.

Bride Katty Malang Mikunug with friends, takes a photo before the wedding on October 21, 2017 in Saguiaran in Lanao del Sur, southern Philippines. Paulo Mamayo Ambor, 22, a resident of Marawi who got displaced by the fighting between government troops and IS-inspired militants, weds Katty Malang Mikunug, 22, a resident of an adjacent town in Saguiaran. Philippines President Rodrigo Duterte declared Marawi liberated, following the death of Abu Sayyaf leader Isnilon Hapilon and one of the Maute brothers, Omar Maute, after nearly five months of fierce urban battle inside the besieged city. The fighting started May 23, and left more than 1,000 people dead, whilst displacing at least 400,000 people. (Photo by Jes Aznar/Getty Images)

Enthusiasts gathered at Cad East in Snowdonia National Park, England to take pictures of F-15 Eagle fighters as they completed the Mach Loop, November 2017. (Photo by Caters News Agency)

Tactics reminiscent of the early American frontier days are now being used in Vietnam. Lieutenant Commander Donald D. Sheppard, UBN, of Coronado, California, aims a flaming arrow at a bamboo hut concealing a fortified Viet Cong bunker on the banks of the Bassac River, Vietnam on December 8, 1967. (Photo by AP Photo)

Minnie Mouse, left, and Katy Perry attend a ceremony honoring Minnie with a star on the Hollywood Walk of Fame on Monday, January 22, 2018, in Los Angeles. (Photo by Mario Anzuoni/Reuters)