2015年12月25日，旨在促进亚洲区域建设互联互通化和经济一体化进程的亚洲基础设施投资银行正式成立。全球迎来首个由中国倡议设立的多边金融机构。这表明我国（    ）

①在国际事务中发挥主导作用      ②积极推动区域经济交流与合作

③已成为发达国家和经济强国      ④展示了务实，负责任大国形象

我市去年约有50 000人参加中考，这个数据用科学记数法可表示为____人．

   Millions of stars are travelling about in space. A few form groups which travel together, but most of them travel alone. And they travel through a universe which is so large that one star seldom comes near to another. For the most important part each star makes its journey in complete loneliness, like a ship on an empty ocean. The ship will be well over a million miles from its nearest neighbour. From this it is easy to understand why a star seldom finds another anywhere near it.
   We believe, however, that some two thousand million years ago, another star wandering(漫游) through space, happened to come near our sun just as the sun and the moon raised its tides(潮汐) on the earth, so this star must have raised tides on the surface of the sun. But they were very different from the small tides that are raised in our oceans; A large tidal(潮汐的) wave must have travelled over the surface of the sun, at last forming a mountain so high that we cannot imagine it. As the cause of the disturbance came nearer, so the mountain rose higher and higher. And before the star began to move away again, its tidal pull had become so powerful that this mountain was torn to pieces and thrown off small parts of itself into space.
   These small pieces have been going round the sun ever since. They are the planets.

如图，在平面直角坐标系xOy中，过点A（﹣6，0）的直线l₁与直线l₂：y=2x相交于点B（m，4）．

     April Fool's Day is supposed to be a day to play jokes on others in hopes of getting a good laugh and making one feel like a fool. However, the April Fool's Day of 2013 was quite different for my morn and me.

     That day my friend Jimmy and I were playing a game. I had dropped down from a bar(横木) many times in the past without ever having a problem, but that day the simple act of dropping to the ground became a nightmare(噩梦). I broke my arm.

Jimmy's dad heard my crying and rushed out to see what was going on. When he saw the

problem, he quickly put me into his truck and went inside to telephone my mom and let her know he would take me to the hospital. As that day was April Fool's Day, Mom was not buying it and really thought all this was a big joke. Mom was finally convinced(说服) by Jimmy's room. When she saw me, she broke down in tears because she felt so bad--she originally (起初) thought this was just a big prank(恶作剧).

      I guess one could compare this to the story of "The Boy Who Cried Wolf". Since I had pulled pranks before, it is no wonder that my morn didn't believe it. I as well as my morn was made to look like a fool that day. We both learned a valuable lesson.