博士 是授予的最高学位，因此需要在书面论文中提出的知识和研究成果方面的最高水平和成就。尽管没有特定的课程要求，但大多数博士生大约需要花费四到五年的时间来攻读博士学位，其中包括研究工作和学士学位后的大约50至60个学时。<br> <br> 2004年12月下旬，有记录的历史上最破坏性的海啸席卷了印度尼西亚苏门答腊岛，使整个社区从地图上消失了。跨越索马里的印度洋，同一波浪在数小时后淹没了海岸线。最终的死亡人数来自11个国家/地区的四分之一的人口。数百万人无家可归。联合国将重建费用固定在120亿美元以上。
The Ph.D. is the highest degree awarded, and as such requires the highest level of proficiency and achievement, both in knowledge and in the performance of research presented in a written dissertation. While there are no specific course requirements, most doctoral students spend approximately four to five years working toward a Ph.D., which includes research and approximately 50 to 60 credit hours beyond the bachelor's degree. In late December 2004, the most-devastating tsunami in recorded history swept ashore in Sumatra, Indonesia, wiping entire communities off the map. Across the Indian Ocean in Somalia, the same wave inundated the coastline hours later. The eventual death toll A quarter of a million people in 11 countries. Millions more were left without homes. And the United Nations pegged the cost to rebuild north of 12 billion.