1. Many students spend months researching and writing their dissertations.
许多学生花费数月时间研究和写作他们的论文。

2. The professor assigned a 20-page dissertation on the impact of globalization.
教授布置了一篇关于全球化影响的20页论文。

3. She defended her dissertation successfully and earned her doctoral degree.
她成功地答辩了她的论文，获得了博士学位。

4. The library has a collection of dissertations written by former students.
图书馆有一些前学生写的论文集。

5. Writing a dissertation requires careful planning and thorough research.
写一篇论文需要仔细的计划和深入的研究。

6. The professor praised the student for the originality of her dissertation.
教授赞扬了学生的论文的独创性。