Xicheng 2moIf I could go back in timeOne of the most popular topics in the history of science fiction has been the idea of time travel.When I was a child, I often dreamed about a time machine that would allow me to “save” certain moments of my life, so that in case I failed to do something, I could always “load” my life from a checkpoint. As I grew _ (13), my life experiences gradually became more diverse (多样的). In many situations, I had no idea how to act properly, what decisions to make, what path to follow; _ (14), I made mistakes. While many of my actions back then turned out for the good in the future, some mistakes provided many painful moments for me and people around me. Mistakes are certain to happen, but they allow us to learn, _ (15) ourselves, and drive us to change for the betterand still sometimes I would like to jump into a time machine, go back a couple of years ago, and make _ (16).Would I try to make other people act in a different way? I think no. I would rather _ (17) myself about the awaiting consequences (后果) of my most careless decisions. I would talk to a long-haired teen holding his first cigarette and tell him: “Dont do that.” So many warnings I would give to myself that sometimes I think: was it really me who did this and that?Having a time machine would make life easier. Perhaps, it is true. But what I think more often now is that living without this teaches us responsibility, about oneself, about important people to us, about ones own life. And besides, our _ (18) make us what we are today. Today I am a person leading a healthy, active lifestyle; I try to live each day to fullness in order to _ (19) nothing.If I could go back in time, I would try to make my _ (20) better. This is what our parents always try to do when we are children. But you know what? I am glad that no time machine has been invented.13. A. wiser B. older C. stronger D. richer14. A. naturallyB. directly C. suddenlyD. luckily15. A. love B. enjoy C. develop D. trust16. A. wishes B. journeys C. decisions D. corrections17. A. warn B. comfortC. advise D. criticize18. A. dreams B. changes C. mistakes D. responsibilities19. A. fear B. costC. miss D. regret20. A. family B. future C. childhood D. educationCResearch has already suggested that opening a book may help improve brain function and reduce stress. Now, a team led by Joanna Sikora of the Australian National University is looking into the benefits of growing up around a book-filled environment; the researchers new study suggests that homes with libraries can arm children with skills that last well into adulthood.The study looked at data from 160, 000 adults from 31 countries, including the United States, Australia, Turkey and Chile. Participants (参与者) filled out surveys with the Programme for the International Assessment of Competencies, which measures proficiency (水平) in three areas: literacy (读写能力), numeracy and information communication technology. People, 25 to 65 years old, were asked to tell how many books were in their house when they were 16 years old. The research team was interested in this question because home library size can be a good sign of “book-oriented socialization”. Participants were able to choose from a given range of books that included everything from “10 or less” to “more than 500”.The surveys, which were taken between 2011 and 2015, showed that the average (平均的) number of books in participants childhood homes was 115, but that number varied widely from country to country. The average library size in Norway was 212 books, for example; in Turkey, it was 27. In all, however, it seemed that more books in the home was linked to higher proficiency in the areas tested by the survey.The effects were most marked when it came to literacy. Growing up with few books in the home resulted in below average literacy levels. Being surrounded by 80 books raised the levels to average, and literacy continued to improve until libraries reached about 350 books, at which point the literacy rates leveled off. The researchers saw similar things when it came to numeracy; the effects were not as pronounced with information communication technology tests, but skills did improve with increased numbers of books.So, what does the new study tell us? Take, for example, an adult who grew up with hardly any books in the home, but went on to get a university degree compared to an adult who grew up with a large home library, but only had nine years of schooling. The study found that both of their literacy levels were almost the same. “So, literacy-wise, bookish childhood makes up for a good deal of educational advantage,” the study authors write.Further research is needed to decide exactly why exposure to (沉浸在) books in childhood encourages valuable skills later in life, but the study offers further evidence to suggest that readi