The Cretaceous period ended about 65 million years ago, a mass extinction due to impact of an asteroid at Chicxulub in Mexico wiped out the dinosaurs, except for the birds.是什么意思_The Cretaceous period ended about 65 million years ago, a mass extinction due to impact of an asteroid at Chicxulub in Mexico wiped out the dinosaurs, except for the birds.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句