肿瘤学

例句：

1. 1. Tumors are the most common cause of death in the United States.
   肿瘤是美国最常见的死因。
2. 2. The researcher focused on the development of new cancer treatments.
   研究者专注于开发新的癌症治疗方法。
3. 3.Cancer is a disease that affects millions of people worldwide.
   癌症是一种影响全球数百万人的疾病。