补全对话

A: Hello, Betty. ____ ?

B: Hello, Tony. Our classroom is really big. There are 46 students in my class.

____ ?

A: There are 45 students in my class.

B: ____?

A: Yes, there are two maps on the wall, a map of the world and a map of China.

B: ____?

A: No, there isn't a TV in our classroom. But there is a computer.

B: ____?

A: It's on the teacher's desk. Oh, it's time for class(该上课了). Let's go. Bye.

B: Bye.

 水是我们日常生活必不可少的物质，下列有关水的说法正确的是（　　）

现在各国都注重发展经济、科教事业，以增强综合国力。这是因为（     ）

①经济力与科技力是综合国力的基础

②综合国力是主权国家赖以生存和发展的精神根基

③综合国力是一个国家捍卫国家利益、实现国家目标的能力，能衡量其国际地位

④综合国力是决定国际关系的关键因素