Hawaii's Birds Threatened by Invasive Predators, Habitat Loss Many people think of the Hawaiian islands as a Pacific paradise, a string of tropical islands lush with exotic flora and fauna. But the islands' native species - especially birds - have be

发表于:2018-12-16 / 阅读(42) / 评论(0) 分类 VOA标准英语2012年(七月)

Albert has been a Crip since age 12. He is one of the first generations of the Los Angeles based Gang, a group known as the Original Baby Gangsters. His seniority puts him near the top of the Crips' national hierarchy. Here in Lebanon, he runs a crim

发表于:2018-12-30 / 阅读(48) / 评论(0) 分类 国家地理2007年

--The irony for many predators is they are very concerned about injuring themselves. Even the toughest most well-armed man-eaters regularly come face to face with prey that can kill them. Whether you had the jaws of a Tyrannosaurus Rex, or are armed

发表于:2019-01-23 / 阅读(148) / 评论(0) 分类 探索与发现2013年

Nothing this large would achieve powered flight until the 20th century, 65 million years later. And Quetzalcoatlus still may hold the record for flight duration. Probably stay aloft for a week. Probably it could have gone for 25, 26,000 miles in a si

发表于:2019-01-23 / 阅读(82) / 评论(0) 分类 探索与发现2013年

I think that a big pterosaur on the ground wouldve been spooky because they would be moving around on all fours. Theyd probably have those sort of quick, precise movements like birds, but theyd be huge. Quetzalcoatlus lives by its own rules. Most mea

发表于:2019-01-23 / 阅读(90) / 评论(0) 分类 探索与发现2013年

Mighty carnivores ruled a dangerous world in the Cretaceous Period. But being a super predator like Tyrannosaurus Rex is not easy. Just surviving to adulthood is a major feat, one that takes a decade or more of killing and eating some of the meanest

发表于:2019-01-23 / 阅读(80) / 评论(0) 分类 探索与发现2013年