第6题: [单项选择]We see distant galaxies as they were long, long ago because ______. A. they were closer together then B. the universe has always looked as the same C. their light takes so long to reach us D. they have travelled such a long way 参考答案:C 答案解析:[解析] 由短文第四段中的Since the very distant galaxies are thousands of millions of light years away, then we