Had Toutatis hit the Earth, it would have had the explosive impact of a one million megaton bomb, many times the total nuclear arsenal of the superpowers, and destroyed all life on the planet. 一旦Toutatis真的撞击地球，它的爆炸效果相当于100万兆吨级炸弹，是超级大国全部核武库的好几倍，摧毁地球全部生命。
a one megaton nuclear bomb 一枚一百万吨级的核炸弹
How much is a one way ticket to Boston? 到波士顿的单程票多少?
How much is it for a one day pass? 一天通用票要多少钱?
You should pay $28 for a one way ticket. 单程票为28美元。
And then, within minutes, the isolated, verdant mountains above China's most famous panda reserve exploded as if hit by a megaton bomb. 然后在几分钟之内，中国最闻名的熊猫保护区之上孤兀而青翠欲滴的大山宛若被兆吨炮弹袭击轰然爆炸。