第谷是历史上最后一位不用望远镜观测的天文学家。

___Tycho was the last major astronomer to work without a telescope.

天文学家们经常通过望远镜观测第谷环形山。

Astronomers often observe the ___Tycho crater through telescopes.

泰科是我们班上唯一一个来自丹麦的同学。

___Tycho is the only student in our class who comes from Denmark.