媒體英語會帶大家一起學習 BBC 撰稿人在報道世界大事時常用到的單詞和短語。

世界著名的美國亞利桑那州的大峽谷可能比先前想象的歷史要短得多。新的科研顯示這一世界奇的形成僅有五至六百萬年的時間。這比先前的說法要短得多。以前的研究聲稱大峽谷已經有七千萬年歷史。以下是 BBC 科學事務記者 Jonathan Amos 發(fā)回的報道：

Millions of tourists are drawn each year to the Grand Canyon to see its impressive rocks, which record nearly two billion years of Earth history. Running for almost 450km and to a depth of 1,800m, it is almost too vast to take in.

Its huge scale has also been problematic for scientists who've spent years gathering data from different locations through the canyon to try to work out its true age.

Some of the most recent investigations had indicated an ancient origin, while others thought it was much younger.

Now a new study in the Nature Geoscience journal pulls it all together. It finds, yes, the Grand Canyon has very old segments, but the full system was only cut into the form we know today by the Colorado River just over five million years ago.