1. He must have come to know those philosophers through secondary or tertiary sources. 他一定是通过第二手或第三手资料了解那些哲学家的。
2. The Tertiary Period was separated into division of time that were equal in length. 第三纪被划分为等长的时间单位。
3. This change in plankton found in marine deposits is what marks the boundary between the Cretaceous and the Tertiary. 海洋沉积物中浮游生物的这种变化标志着白垩纪和第三纪的分界线。
4. Charles Lyell made a good estimate of the Tertiary Period from the fossil record, but his method could not be extended to earlier geological periods. 查尔斯·莱尔根据化石记录对第三纪作出了很好的估计，但他的方法不能扩展到更早的地质时期。
5. In many countries, part-time studying is not exceptional: on average across OECD countries, part-time students in 2016 represented 20 percent of enrolment in tertiary education. 在许多国家，半工读并不罕见。2016年经合组织（OECD）成员国半工读学生人数平均占高等教育入学人数的20%。
