《史记·周本纪》记载:“平王立，东迁于洛邑，避戎寇。平王之时，周室衰微，诸侯强并弱，齐、楚、秦、晋始大，政由方伯。”其中齐秦楚晋等诸侯国名称的出现是源自于西周的是（    ）

《双十协定》中，国共两党未达成协议的问题有（　　）

①“必须共同努力，以和平、民主、团结、统一为基础“

②“长期合作，坚决避免内战，建立独立、自由和富强的新中国”

③国民大会问题

④军队整编问题

    What do you read when you travelling by train? What about other passengers? Perhaps a woman____(sit) near you is reading a romantic novel. A man is reading a serious biography about a politician. And there's a student reading an English textbook.

    What do their____(choice) say about them? Do you judge them by____they reading? I have to tell you that your impressions of them may be____(complete) wrong. The woman reading the romantic novel could be a ____(law). She just wants a light read to take her mind off work. The man reading the biography wants you____(consider) him knowledgeable, and he is just ____(show)off. The student reading the textbook isn't a student at all. She's an English teacher.

    Publishers know people are ____ (concern)about what they read on public transport and put out different versions (版本) of a cover For example, books about Harry Potter have an____ (interest)cover for young readers and then another more serious version for adults.

    So next time you see what other people are reading on a train don't jump to any conclusions.

    Here is a situation ____ you could say, "Don't judge a book by its cover.”

$+\frac{1}{{(n+1)}^2}$ ．设 $S=\sqrt{S_1}+\sqrt{S_2}+$ … $+\sqrt{S_n}$ ，则S=____ （用含n的代数式表示，其中n为正整数）．

①完善党的执政方式      
②发挥党员的先锋模范作用

③有效制约和监督权力   
④行使管理国家的权力