VOA慢速英语:Planetariums Take Viewers on a Trip Through Space

1.Since ancient times, humans have worked on ways to understand and represent the movement of the stars and planets.

work on致力于…

例句：He has been working on a new novel for over a year now.
      近一年多来, 他一直在写一部新小说。

2.Eisinga made his device out of wood, metal nails, a clock and nine weights.

made out of由...制成

例句：The Box is made out of cedar wood.
      这盒子是用杉木做的。

3.See, that's how night sky is supposed to look.

be supposed to被认为,据说,应该

例句：You are not supposed to do that.
      你不可以做那个。