问题 单项选择题

红外激光胶片和氦氖激光胶片的吸收光谱值分别是

A.633nm和550nm
B.633nm和360nm
C.633nm和980nm
D.820nm和633nm
E.820nm和430nm

答案

参考答案:D

解析:红外激光胶片的吸收光谱值为820nm,氦氖激光胶片的吸收光谱值为633nm。

阅读理解

阅读简答:阅读下面短文,简要回答文后问题。

     History is the story of us, human beings. Everyone who has lived and everything that has happened are

part of history. But history is not only what happened in the past. The word also means the study of the past,

through old written records and other kinds of facts.

     Why do we study history? One reason is that we enjoy it. A good story is even better if it is true, and

history is full of good stories, though they can be terrible too. A more serious reason is to understand ourselves

and the world we live in. To understand events happening now, we need to know their causes. We cannot

understand the present if we know nothing about the past. History helps to explain why things are the way they

are.

     Of course, history books cannot tell us everything about the past, not even everything that is recorded. A

history of the world has to pick out the people and events that changed the world.

     Since ancient times, great civilizations have appeared in different countries and regions. Usually, only three

or four existed at the same time. While they lasted, they changed the lives not only of their own people, but of

their neighbors too.

注:(1) civilizations 文明 (2) exist 存在 (3) region 地区

1. What is history?

     __________________________________________________________

2. How do we study history?

    __________________________________________________________

3. Why do we study history? Please give two reasons. 

    __________________________________________________________

    __________________________________________________________

4. What have appeared in different countries and regions since ancient times? 

    __________________________________________________________

5. What title can you give to the passage? 

    __________________________________________________________

多项选择题