So if you've been following the news, you've heard that there's a pack of giant asteroids headed for the United States, all scheduled to strike within the next 50 years.
如果，你一直有看最近的新闻， 你肯定听说过有一群巨大的小行星 朝着美国冲过去， 所有的这些小行星都会在接下来50年里，一个接一个地袭击我们。