大多数鸟类体内具有气囊，气囊在鸟飞行时所起的作用不包括（　　）

北回归线所指的纬线是（    ）

阅读短文，下列问题

    Every morning my father buys a newspaper on his way to work. Every evening my mother looks through magazines at home. And every night, I look at the posters with photos of David Beckham and Yao Ming on my bedroom wall before I go to sleep. Can we imagine life without paper or print?

   Paper was first created about 2,000 years ago, and has been made from silk, cotton, bamboo, and, since the 19th century, from wood. People learned to write words on paper to make a book. But in those days, books could only be produced one at a time by hand. As a result, they were expensive and rare. And because there weren't many books, few people learned to read.

    Then printing was invented in China. When printing was developed greatly at the beginning of the 11th century, books could be produced more quickly and cheaply. As a result, more people learned to read. After that, knowledge and ideas spread quickly.

Today information can be received online, downloaded from the Internet rather than found in books, and information can be kept on CD-ROMs or machines such as MP3 players.

    Computers are already used in classrooms, and newspapers and magazines can already be read online. So will books be replaced by computers one day? No, I don’t think the Yao Ming poster on my bedroom wall will ever be replaced by a two-metre-high computer!

①随着计算机科学技术和互联网技术的快速发展，网络写手逐渐作为一个职业发展起来。一时间网络平台的文坛泥沙俱下，多数作品难称文学之名。

②对于面临高考的学生来说，考前宵衣旰食、埋头读书是再正常不过的事，因为要博得一个光明的未来，必须付出努力。

③莫言小说最先征服你的并不是故事和人物，而是语言。那一个个平淡的文字背后深藏着穿云裂石的哀痛和精彩斑斓的怜爱。

④当地时间周三晚，中国长征七号火箭重新进入大气层，刚好经过加利福尼亚附近，美国人着实吓了一跳。有些人粤犬吠雪，甚至怀疑这些火球是飞机解体。

⑤我上高中后家里负担日益加重，父母亲外出打工长年难归。我要率先垂范，给弟弟给个榜样，不让父母的辛苦白费。

⑥这些年来，随着人们接触的新事物越来越多，观念越来越开放，再加上经济水平的不断提高，中国人的自驾游活动搞得风生水起。