美国政府的官方网站
知道是官方网站的原因
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A lock ( LockA locked padlock ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites. .
This page has not been translated into 简体中文. Visit the 简体中文 page for resources in that language.
458. National Oceanic and Atmospheric Administration “Tsunamis” webpage
