教育部要求各级学校于2010年春节期间组织学生参与“给祖国母亲拜大年”活动。拜年内容为：一拜壮美河山，二拜炎黄始祖……中华民族这种重视血缘亲情的文化传统与下列 哪一制度相关

2008年11月，英国海军在获得索马里政府授权后，进入索马里海域打击海盗，并与索马里海盗交火。但在近代史上，英国曾经“靠着一群海盗起家”，而成为（   ）

①“三角贸易”的主要经营者                               ②18世纪世界上最强大的殖民国家

③黑人奴隶的最大使用国                                     ④甘蔗、棉花、烟草的最大出口国

   “Cool”is a word with many meanings．Its old meaning is used to express a temperature that is a little bit cold．As the world has changed，the word has had many different meanings． 
   “Cool”can be used to express feelings of interest in almost anything．
   When you see a famous car in the street，maybe you will say，“It's cool．”You may think，“He's so cool，”when you see your favourite footballer． 
   We all maximize（扩大） the meaning of“cool”．You can use it instead of many words such as “new” or “surprising”．Here's an interesting story we can use to show the way the word is used．A teacher asked her students to write about the waterfall（瀑布）they had visited．On one student's paper was Just the one sentence，“It's so cool．Maybe he thought it was the best way to show what he saw and felt． 
   But the story also shows a scarcity（缺乏）of words．Without “cool”，some people have no words to show the same meaning．So it is quite important to keep some credibility（可信性）．Can you think of many other words that make your life as colourful as the word “cool”？ I can．And I think they are also very cool．

若实数a、b满足a+b=2,则2^a+2^b的最小值是 （　　）