People started looking at stars a very long time ago. Modern science expanded our understanding too, and we know the Earth is a small planet that goes around an ordinary star in the Milky Way Galaxy. We also know that there are more than 100 billion galaxies in the universe. We live on a small planet in a very large universe. But there are many questions we haven’t answered yet. For example, …………..……………………………………………………..
Last century scientists discovered that there are other planets in the universe. However, all the planets that they found are much bigger than the Earth, and they probably don’t have life on them. But who knows?
(Texto adaptado de MILNER, Martin. World English 1. Boston: HEINLY Cengage Learning, 2010.)
De acordo com o texto e com as normas gramaticais, a pergunta que completa CORRETAMENTE a lacuna acima é