1、美国英语单词：U.S.A。the United States of America，英 [ðə juˈnaɪtɪd steɪts ɒv əˈmerɪkə] 美 [ðə juˈnaɪtɪd steɪts əv əˈmerɪkə]。
2、美国对空袭很快作出了反应。The US delivered an early riposte to the air attack.
3、美国每四年举行一次总统选举。In America, presidential elections are held every four years.