阅读理解

    Peng Liyuan, wife of President Xi Jinping, has drawn extensive attention from people both at home and abroad for her charisma and grace. Accompanying her husband on his first overseas trip after becoming president, Peng Liyuan exhibited graceful demeanor, a pleasant personality and well-chosen dress, prompting people to coin the term “Liyuan style”.

    Peng Liyuan, as one of China’s best-known singers, was popular among Chinese people long before her husband became the president. Loved by her fans, she has been in touch with the people for years.

    “Liyuan style” is not only representative of a fashion idol, but also overpass cultural and diplomatic barriers. The beautiful handbags Peng has carried, and the plain but elegant and delicate dresses she has worn have become popular. Her choice of clothing, made-in-China instead of luxurious foreign brands, shows her belief in domestic dress designs.

    But “Liyuan style” is not only about clothing and a woman’s paraphernalia. It is also about diplomacy and promoting China’s soft power. In Moscow, Peng visited a boarding school for orphans and children estranged (疏远) from their parents, encouraging them to strive for a better life, which brought out the maternal side of her character. In Tanzania, she donated sewing machines and school bags to women and children. And as a World Health Organization ambassador in the fight against AIDS, Peng is devoted to many public causes, including those relating to charity and healthcare.

    Some observers have already started saying that Peng's activities have become part of public diplomacy in China.

Also, “Liyuan style” has boosted the confidence of the Chinese people. Modem but not flashy, elegant but not arrogant, Peng has all the virtues of a Chinese woman and carries them to the international stage.

    Since the 18th Party Congress and the annual sessions of the NPC and CPPCC, the country’s new leadership has vowed to adopt a down-to-earth work style to connect with the people. Peng’s plain but elegant style shows that thriftiness and an earthy style need not be drab and boring.

    So it can be said that Peng's first appearance on the international stage has kicked off well.

设N_A为阿伏伽德罗常数的值，下列叙述正确的是（   ）

已知四边形ABCD的对角线AC与BD交于点O,给出下列四个论断

①  OA＝OC    ②  AB＝CD    ③  ∠BAD＝∠DCB    ④  AD∥BC

请你从中选择两个论断作为条件,以“四边形ABCD为平行四边形”作为结论,完成下列各题：

某几何体的三视图如图所示，则该几何体的体积是（   ）

每年4月23日，是联合国教科文组织确定的“世界读书日”。江苏省近几年也在推出“书香江苏”建设。某中学为营造“书香校园”的文化氛围，开展了一系列活动，如果你参加此次活动，请你一起探究下列问题：