Установите последовательность пропущенных в тексте слов.
The Universe contains everything that exists – not only the 1_______ and everything on it, but also all the planets, stars, and galaxies, and the space in between them. The sun, at the center of the solar system, is just one of about 100 billion stars in our galaxy, or collection of stars, called the Milky Way. 2_______ have estimated that there are about 100 billion other galaxies in the universe. Most scientists 3_______that the universe formed about 15 billion years ago in an enormous explosion called the big bang. They also think that 4_______ is expanding.
Earth
astronomers
think
the universe