demarcation between science and pseudo-science

例句：

1. 1. The demarcation between science and pseudo-science is clear.
   科学与伪科学的界限是清晰的。
2. 2.The government has set up a demarcation line to prevent illegal immigration.
   政府已经设立了一道分界线，以防止非法移民。
3. 3.The demarcation of the two countries has been a topic of debate for years.
   这两个国家之间的分界线一直是多年来的争论话题。