Prince William and Kate Middleton spent some time learning about the work being done at the Ukrainian Cultural Centre in London, where volunteers are mounting a humanitarian effort to help those affected near and far.The Duke and Duchess of Cambridge made the visit Wednesday and were greeted by Ukraine's ambassador to the U.K., Vadym Prystaiko and his wife, Inna. The ambassador and his wife gave William and Kate a tour of the facility, where the royals met with members of the Ukrainian community in London and volunteers.Kate and William were photographed wearing lapel pins in Ukraine's flag colors, and they listened intently as volunteers walked them through their efforts and the challenges they face trying to get the material to those who need it most.