Mei Lun and Mei Huan have been the first giant twin pandas born in the US since 1987.  The names of these twin male giant panda cubs  were announced at Atlanta Zoo last year. Lun Lun, a 15-year-old giant panda, gave birth to the cubs on July 15, 2013. Zoo officials followed Chinese custom and named the brothers after waiting 100 days. Until then, they were simply known as "Cub A" and " Cub B".     Mei Lun and Mei Huan are the first twin panda cubs to survive in the Unite States. "We're delighted to finally be able to place two youngsters with names. They have not only made a mark on the history of Atlanta Zoo, but also have made history in the US," Raymond B. King , the zoo's president and CEO, said in a statement. Atlanta Zoo teamed up with Good Morning America that month to put the pandas' names to a public vote. China's Chengdu Research Base of Giant Panda Breeding provided the choices of names. In just 13 days, 51,000 votes poured in on the show's website.     Under a deal between China and the US, giant pandas originally from China are only lent to foreign zoos for scientific study for several years. Zookeepers at Atlanta Zoo are giving regular updates on the twins' progress in an online blog. Mei Lun and Mei Huan are the fourth and fifth offspring  of Lun Lun and a male giant panda named Yang Yang. The pandas made their first public appearance in a US exhibit last fall. For the three months before their appearance, the online world had watched the twins grow strong and healthy. "We share this joy with our colleagues  in China and with the cub's fans around the world," King said. What can be inferred from the passage?
Yang Yang belongs to America. The two cubs are not in good health. Yang Yang is the father of the twins. The cub's fans haven't watched the twins in the zoo.