单选题：What is the reason mentioned in the passage that the laser b

题目分类：英语四级
题目类型：单选题
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题目内容：

What is the reason mentioned in the passage that the laser beam is so strong? A．It sends out light to cover a wide area．
B．It has many sources of light.
C．It is a highly concentrated beam of light．
D．The source of its heat comes from the sun.

参考答案：

答案解析：

The Reader，s Guide is a green—bound index which provides a g

The Reader，s Guide is a green—bound index which provides a guide to very latest

分类：英语四级题型：单选题

The author suggests that people should go to the library for

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分类：英语四级题型：单选题

第(45)题__________

第(45)题__________

分类：英语四级题型：单选题

保证金分为交易保证金和结算准备金，交易保证金是指未被合约占用的保证金，结算准备金是指已被合约占用的保证金。（　　）

保证金分为交易保证金和结算准备金，交易保证金是指未被合约占用的保证金，结算准备金是指已被合约占用的保证金。（　　）

分类：英语四级题型：单选题

随着市场经济的发展，发行证券已成为资金需求者最基本的筹资手段。（　　）

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分类：英语四级题型：单选题