This is considerably less than the height attained by the radioactive cloud in an air burst. 这比在空中爆炸中原子云所能达到的高度要低得多。
From the Cuban missile crisis and the fear of a atomic cloud, to today's enduring mistrust of government, communism remained the country's bogeyman. 从过去的古巴导弹危机与原子云恐惧疑忧，到现在对政府长期的心存疑虑，共产主义在美国仍是用来吓唬小孩的妖怪。
