1. The astrolabe was used by ancient sailors to navigate the seas.
古代水手使用星盘来航行。

2. The astrolabe is a tool used to measure the altitude of stars and planets.
星盘是用来测量星星和行星的高度的工具。

3. The astrolabe was an important instrument in medieval astronomy.
星盘在中世纪天文学中是一个重要的仪器。

4. The astrolabe was invented by the Greeks in the 2nd century BC.
星盘是由希腊人在公元前2世纪发明的。

5. Today, the astrolabe is mainly used for educational purposes and historical reenactments.
今天，星盘主要用于教育目的和历史再现。

6. The astrolabe was a complex instrument that required skilled use to navigate accurately.
星盘是一个复杂的仪器，需要熟练的使用才能准确导航。