当代中国最基本的国情是（   ） 

阅读《龙卷风》 一文，完成小题。
       ①盛夏季节，当你收听台风天气预报的时候，经常可以听到“台风中心风力在12级以上”这样的话，似乎“12级”就是风力之“最”了。自然界中有比这更大的风吗？有，那就是龙卷风。
      ②龙卷风俗称“龙吸水”，这也许是它漏斗状云柱的外形很像神话中的“龙”从天而降，把水吸到空中而得名的吧。实际上，它是从雷雨云底伸向地面或水面的一种范围很小而风力极大的强风旋涡。
      ③龙卷风的风力极大。在龙卷风中心附近，水平风速每秒可达100米以上，极端情况，可达300米。12级风的风速相当于每秒30多米，要和龙卷风相比自然就大为逊色了。如此罕见的巨大的风，造成的破坏异常惊人。当它触及地面时，可以把人畜像开玩笑似的卷到空中，再扔下来，它可以“倒拔垂杨柳”，摧毁建筑物，甚至像利剑似的把坚固的高楼大厦削掉一角。1956年9月24日，上海曾出现过一次龙卷风，它竟然把一个三四层楼高的110吨的储油罐举到15米的空中，然后把它甩到100多米以外的地方。1925年美国曾出现过一次强大的龙卷风，造成2000多人伤亡。为什么龙卷风的风力这么大呢？主要是龙卷风内的空气大量逸散，使龙卷风中心空气十分稀薄，气压很低，与外围空气的气压差特别大。台风中心和它外围空气平均每100公里差20毫巴（压强单位），而龙卷风中心与外围空气只要相差20米，气压差就达20毫巴。气压梯度越大，风力也就越大，难怪龙卷风的风力要比台风大上好多倍了。
      ④龙卷风涉及的范围很广泛。1927年美国北卡罗来纳州的一次龙卷风，在它经过的 15平方米的范围内，大树连根拔起，但是靠近这股龙卷风的地方则安然无恙。
      ⑤龙卷风可以事先预测出来，气象雷达就是监视龙卷风的一种很好的工具。

    The meanings of colors play an important ____in our world. What a color pass to a person of the west, may be very ____to someone in the east. While a bride(新娘) may wear white to her wedding (婚礼) in Europe or America, a bride ____China may choose to wear a traditional red dress.

Here are some ____and what they represent (代表，象征) to various people of the world.

    RED

    In China red is a ____of luck and is used for many celebrations such as wedding and at the beginning of the New Year. In the United States red represents love and is used during Christmas and so on. Red is also represents ____and power in the west.

    BLUE

    People around the world think____and the sky with the color blue. For this reason, blue is widely ____with peace and calm. But to the Cherokees (切罗基族人), blue meant trouble or failure. In the United States we have come to connect the color blue with sadness.

    GREEN

    In Paris, all garage collectors are clothed in green, drive green trucks and the bins are also green. In many parts of the world,____ has become a symbol of kindness and the earth.

    YELLOW

    Yellow is a color that symbolizes the sun. In the United States, school buses and taxis are often yellow____they can catch the eyes. But to the Egyptians, yellow was a color of mourning (哀悼).