In the text below some words are missing. Drag words from the box below to the appropriate place in the text. To undo an answer choice, drag the word back to the box below the text.
下面的文本缺了一些词。请把词框里的词拖到文中合适的位置；要撤销选择，把词拖回文本下方的词框即可。
Stars and the material between them are almost always found in gigantic systems called galaxies. Our own galaxy, the Milky Way System, happens to be one of the two systems in the Local Group of two dozen or so galaxies. The other is the Andromeda galaxy; it more than one hundred thousand light-years from one end to the other, and it is about two million light-years from us.
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