光量子也同时具有波动性和粒子性，光的波动性的典型表现是什么？（）A、光线按费马原理传

发布时间：2018-11-28 17:54 │ 来源：www.tikuol.com

题型：单项选择题

问题：

光量子也同时具有波动性和粒子性，光的波动性的典型表现是什么？（）

A、光线按费马原理传播

B、干涉和衍射现象

C、光速不变

D、光电效应

考点：物理学物理学题库

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如果等腰三角形的周长为18 ，一条边长为5 ，则其他两边的长分别可能是( )

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给出下列代码片断：
if(x＞0) System.out.println("first");
else if(x＞-3)System.out.println("second");
else System.out.println("third");
请问x处于什么范围时将打印字符串“second”( )

A．x＞0

B．x＞-3

C．x＜=-3

D．x＜=0&x＞-3

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题型：单项选择题

结算人员受理本票申请书时，应认真审查其填写的内容是否（）

A.齐全

B.清晰

C.正确

D.完整

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At the beginning of the twentieth century, North American society held, as an ideal, the Nuclear Family. This presumably perfect residential, social, and economic unit consisted of an adult male, an adult female and their minor children. This structure was thought to be stable and long lasting.
However, a few decades later, the structure of that ideal family was being altered radically even while it was being touted as the structure to be aimed for. Popular magazines bemoaned the loss of the Nuclear Family and its replacement with inferior forms.
There are a number of factors that are acting in concert to apply pressure on the Nuclear Family and generate a variety of new structures. Some of these are:
The definition of marriage has changed somewhat in that few people now consider it to last "until death do us part." The concept of monogamy (the marriage of one man and one woman) has been modified to a form now referred to as serial monogamy (the marriage of one man and one woman at a time). This reflects the increasing equality of women and men in terms of economic advantage and the recognition that many women no longer depend on men for their survival. Women are acquiring independence and have become empowered to make their own choices. With this independence, the need to form a relationship with a man becomes less important. This change embodies the concept that the marriage is temporary and can be terminated by either partner at any time. Associated with this, of course, is the relaxation of the divorce laws and the significant reduction of the shame that had one time been attached to divorce.
The economy of North America has resulted in a two-tier system of a few rich who control most of the resources and a large portion of the population who control almost none of the resources. Because of this, many couples are forced to have both partners with full-time jobs outside the home. There are unintended byproducts of the need for a double income. The most important of these is the replacement of a mother-oriented socialization of children to a "stranger-oriented" socialization system reflected in the growth of the childcare industry. Also, either partner is financially able to end the marriage without significant hardship.
The combination of these changes will in the coming decades have a profound effect on the structure of the family of North America. As a result, the family will be a fluid, constantly changing structure with variable household arrangements as the norm.

What has changed the Nuclear Family in North America

A．People have changed their ideas about marriage.

B．Women become more independent.

C．The economy is changing.

D．All of the above factors are acting together.

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Don’t have time to read anymore Now you can get free, quick literature via email. More than 100,000 people open their email each day to read a chapter of a book, through Chapter-A-Day, an online book club created two years ago. It’s a free email service that provides a short daily reading for busy people, exposing them to literature they may not find on their own, inspiring some to recommit to the reading habit. About 550 public library systems representing over 3,000 branch libraries already have signed up to offer Chapter-A-Day. Via email, participants get about five minutes’ worth of reading every day. After three chapters are emailed, the installments stop, and those who want to keep reading can borrow the book at their public library or purchase it online. Chapter-A-Day has eight free book clubs, and sells thousands of books each month.

Chapter-A-Day started in 1999 when Suzanne Beecher, a lifelong book lover, realized how many of the women who worked part-time for her software development company didn’t have time in their busy lives to read. She decided to type part of a chapter of a book, and send it to her employees through email. The next day she typed a little more, and continued to send literary installments each day. She says she started getting feedback from the staff about how reading made them feel. "They were interested, and realized that, though they didn’t have time in their busy lives for reading, just reading that little bit each day got them back in the habit." Realizing that many other people could benefit, she decided to take the idea even further and start an email "chapter-a-day" book club to help others ease their way back into daily reading. "Reading makes changes in people’s lives," Beecher says.

Pat Dempsey, a librarian at a public library in Ohio, has found Chapter-A-Day helps her library clients get back in the habit of reading. "It’s a different way to get people hooked on hooks," she says.

It can be inferred that through Chapter-A-Day ().

A. public libraries have become crowded with readers

B. Ms Beecher made much money for her software company

C. people begin to read very slowly and patiently

D. people cannot finish reading any book online

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