问题 问答题

如图所示,从发光点A发出的光射到水面后,反射光线经过B点,请画出入射光线、反射光线和折射光线的大致方向.

答案

先作出发光点A关于水面的对称点A′,连接BA′,交平面镜于点O,OB为反射光线,AO为入射光线;

过O点垂直水面作出法线,在水中法线的左侧画出折射光线,注意折射角小于入射角,辅助线用虚线,如图所示:

单项选择题
阅读理解

阅读理解。

     Don't have enough time or money to visit the World Expo (世界博览会) in Shanghai? Don't worry.

Check the official website, Expo Online, at www.expo2010.cn. Without spending any money, you'll feel

like you're enjoying the best of Shanghai.

     Expo Online has two main parts. One is a site tour. It shows you a virtual (虚拟的) park with the same

settings as the real Expo. Moving the mouse, you can look at the 3D pavilions (展馆) from every angle (角度). Online, you won't have to pay to enter and enjoy the pavilions. Haibao, the mascot, will guide you and explain

what you're seeing in either Chinese or English.

     The other part of the website, Expo Carnival (狂欢节), allows you to rebuild the pavilions and play games

with Haibao. You can also upload your photos, videos and diaries there.

     The Web offers lots to see and do, and you don't even have to leave home. Why not check it out?

1. How many main parts does "Expo Online" have?

A. Two.

B. Three.

C. Four.

2. What's the mascot of Expo 2010?

A. Nini.

B. Haibao.

C. Huanhuan.

3. What's the Chinese meaning of the underlined word "upload"?

A. 购买

B. 下载

C. 上传

4. Which of the following is TRUE according to the passage?

A. You can visit the Expo 2010 online without spending any money.

B. Expo Carnival allows you to play games with a mouse.

C. The mascot can explain what you're seeing in three languages.

5. Which of the following is the best title for the passage?

A. Make Enough Money for the World Expo

B. Go to Shanghai to Visit the World Expo

C. Visit the World Expo from your Home