30.If the President can no longer serve, who becomes President?
30.如果美国总统无法履行职责，由谁替代？
Answer: The Vice President
答案：副总统
Explanation: "The President has been shot!"
解释：“总统被射杀了！”
This phrase, or something similar, has been said many times in U.S. history.
这个句子，或与之类似的句子，在美国历史上提到过很多次了。
Being president is a risky job (or a job with many dangers).
担任总统有风险（或危险多的工作）。
Many presidents are assassinated (or killed) or simply die while they are in office (or working as president).
许多总统被刺（或被杀）或仅仅是死于任上。
That's why we have to have a plan for who will be the next president if the current president dies.
这就是为什么我们要事先制定计划，一旦总统死了，谁将继任，成为下一任总统。
When the president can no longer serve (or work), the vice president becomes the next president.
当总统无法履行职责（工作）时，副总统成为下一任总统。
To date (or until now), nine vice presidents have become president when the president could no longer serve.
到目前为止（或直到现在），已有九位副总统因总统无法履行职责而继任。
The first time this happened was in 1841, when President William Henry Harrison died.
第一次发生在1841年，威廉·亨利·哈里森总统死了，
The vice president, John Tyler, had a swearing-in ceremony and took the presidential oath of office, or made a statement promising to do his best while serving as the next president of the United States.
副总统约翰·泰勒宣誓就职，或者发表声明承诺将竭尽全力来当好下一任总统。
Because the order of succession (or the plan for who will become the next president) was clear, there were no problems.
由于继任次序（或谁将成为下一任总统的方案）清晰，所以没有出现任何异议。
译文为秀哈英语翻译，未经授权请勿转载！
