请从下列材料中选取必要的信息，为“世界博览会”下一个定义。

①世界博览会由一个国家的政府主办，有多个国家或国际组织参加。

②世界博览会作为国际性大型展示会，其特点是举办时间长、展出规模大、参展国家多、影响深远。

③世界博览会展现了人类在社会、经济、文化和科技领域取得的成就。

答：________________________________________________

根据所给的汉语提示，转换下列句型。

1. The blue sweater belongs to my mother.  (对画线部分提问)

                              the blue sweater belong to?

2. The red car must belong to your father.   (改为同义句)

    The red car must           _ your _           .

3. Big  Xin is my favorite author.  (对画部分提问)

                              your favorite author?

4. My brother didn't go to school yesterday.  He was ill.(合并成一个句子)

    My brother didn't go to school yesterday                            illness.

5. I can't get online.   Something must be wrong with my computer.   (改为同义句)

    I can't get online.  There                           something wrong with my computer.