根据短文内容，从短文后的选项中选出能填入空白处的最佳选项，选项中有两项为多余选项。

      Secret codes (密码)keep messages private。Banks, companies, and government agencies use secret codes in doing business, especially when information is sent by computer.

     People have used secret codes for thousands of years. {#blank#}1{#/blank#}  Code breaking never lags(落后) far behind code making. The science of creating and reading coded messages is called cryptography.

     There are threemain types of cryptography. {#blank#}2{#/blank#}  For example, the first letters of “My elephant eats too many eels” Spell out the hidden message “Meet me.”

{#blank#}3{#/blank#} You might represent each letter with a number, For example, Let's number the letters of the alphabet, in order, from 1 to 26. If we substitute a number for each letter, the message “Meet me” would read “13 5 20 13 5.”

     A code uses symbols to replace words, phrases, or sentences. To read the message of a real code, you must have a code book. {#blank#}4{#/blank#} For example “bridge“ might stand for “meet” and “out” might stand for “me.” The message “bridge out” would actually mean “Meet me.” {#blank#}5{#/blank#}  However, it is also hard to keep a code book secret for long. So codes must be changed frequently.

A. It is very hard to break a code without the code book.
B. In any language, some letters are used more than others.
C. Only people who know the keyword can read the message.
D. As long as there have been codes, people have tried to break them.
E. You can hide a message by having the first letters of each word spell it out.
F. With a code book, you might write down words that would stand for other words.
G. Another way to hide a message is to use symbols to stand for specific letters of the alphabet.

    These days when someone says a computer has a bug (小虫子) in it, usually they mean that there's a problem with one of its programs. Maybe your computer crashed when you were in the middle of a game.{#blank#}1{#/blank#}

    But back in the early days of computers, a woman named Grace Hopper was part of a team that discovered the very first computer bug.

    {#blank#}2{#/blank#} She had been invited to help program a new computer, the job of which was to quickly deal with the math problems ships used to find their way.{#blank#}3{#/blank#} Then it translated the patterns of holes into the math problems it was supposed to solve.

    One afternoon in 1947 Hopper and her team were running a program. But the computer wasn't giving them the right results.{#blank#}4{#/blank#} They finally ended up taking the computer apart, looking for problems. What did they find? It was a moth (飞蛾)! The moth was blocking some of the holes in the paper—{#blank#}5{#/blank#} Some people think Hopper was the first person to use the word “debug” to mean “get rid of the problems in a computer”.

    Nowadays, many people do not read for pleasure. The Internet and television have become most people's main form of entertainment, and reading is becoming a thing of the past. {#blank#}1{#/blank#} And there are ways to make it even more enjoyable, whether you do it frequently or just for assignments.

    Indentify what kind of reading you want to enjoy.

    Believe it or not, people enjoy different kinds of reading. Some people do research, some people read to learn how to do things, and some people read in order to enjoy stories or poetry. {#blank#}2{#/blank#}

    Realize that there are countless types of reading materials.

    For example, if you want to read stories, keep in mind that there are many types, like romantic novels, creative nonfiction, etc. Don't decide you don't like reading just because you don't like one particular kind of books. {#blank#}3{#/blank#} But in the end, you'll slowly develop an interest in reading.

    Try listening to music.

    {#blank#}4{#/blank#}Soft music is generally received better, but any type will do. It depends on what you like.

    {#blank#}5{#/blank#}

    Find a place that is quiet, well-lit, and comfortable. You can even make a reading comer in your room.

A. Create a good reading environment.

B. Concentrate on what you're reading.

C. Remember, you will have trial and error.

D. Therefore, watching TV plays an important role.

E. Before anything else, figure out why you want to read.

F. For some people, this makes reading more pleasant.

G. However, reading can greatly increase your life experience.

    Bad days happens to many of us. Something makes us sad, angry, frustrated or disappointed. But you still have to get up and go to work. Everything others say to you sounds stupid. {#blank#}1{#/blank#}. Luckily, you can do something about it. Here are some ways to turn around a bad day.

    Accept your bad mood

    Being in a bad mood is not that hard. If you're mad, be mad.{#blank#}2{#/blank#}. This does not give you the right to be rude and unpleasant to others. It just means that you need to recognize and accept your bad mood to be able to do something.

    Tell others

    You can try to keep your bad mood a secret and put on your happy mask. Guess what, you're fooling nobody.{#blank#}3{#/blank#}. Simply tell them“ listen guys, I'm in a really sour mood today. I'm not sure why, but it's nothing to do with what you have done. If I bite your head off, I apologize in advance.”

    {#blank#}4{#/blank#}.

    Spend a few moments to try thinking of at least one or two things that are good: Something you look forward to, such as a person you like at work or something nice that happened recently.

    Take some quiet time

    And if you're having a really bad day, it may be a good idea to withdraw(撤离; 退出)a little if you can. {#blank#}5{#/blank#}. Sit and work somewhere quiet. Take a long bathroom break. Consider going home early or taking the day off.

A. Remember the good

B. It's important to get along well with others

C. Everyone seems to annoy you

D. The best thing to do is to tell the people you work closely with

E. If you're sad, be sad

F. Ask for advice

G. Take a walk in your lunch break

    Movies have documented America for more than one hundred years. Since Thomas Edison introduced the movie camera in 1893  amateur and professional movie-makers have used moving pictures to tell stories and explain the work of business and government. {#blank#}1{#/blank#} By preserving these movies, we will save a century of history.

    Unfortunately, movies are not made to last. {#blank#}2{#/blank#} Already the losses are high. Only 20% of US feature films from the 1910s to 1920s survive. Of the American features produced before 1950, about half exist. For independently produced works, we have no way of knowing how much has been lost.

    For many libraries and museums, the hardest step in preserving movie collections is getting started. The Movie Preservation Guide is designed for these organizations. {#blank#}3{#/blank#} These institutions have collections of moving pictures but lack information about how to take care of them. The guide contains basic facts for "beginners"—professionals trained in history but unschooled in this technical area.

    The guide grew from user workshops at Duke University. At the sessions, beginners talked with technical experts about what they needed to know to preserve and make available their movie collections. {#blank#}4{#/blank#}

    Following the advice, the guide describes methods for handling and storing moving pictures that are practical for research institutions with limited resources. {#blank#}5{#/blank#} The guide has been translated into Chinese, Japanese and Korean.

A. "Keep it simple!" was the advice of the discussions.

B. They'll be damaged within years if not properly stored.

C. These organizations are the first to save American movies.

D. It is organized in chapters and includes case studies and charts.

E. It introduces movie preservation to nonprofit and public institutions.

F. They show how generations of Americans have lived, worked and dreamed.

G. They store the original movies and new ones under cool-and-dry conditions.

    It's sometimes hard to understand a teenager. It's even harder if a teenager doesn't agree with you.{#blank#}1{#/blank#}

    Listen to what the teenager has to say. {#blank#}2{#/blank#} While you may not entirely agree with what he's saying, the tension will be lessened if the teenager feels like you are listening and trying to understand him. Also, he might return the favor and give you the chance to talk as well. It's best to have a conversation where both of your opinions matter rather than fight and possibly hurt each other in the process.

    Understand that while teenager may appear grown up and perhaps even sound matured, his mind has not fully developed, and he cannot think like an adult all the time. {#blank#}3{#/blank#} However, this doesn't mean you're completely right or he deserves to be ridiculed or treated like a child.

    {#blank#}4{#/blank#} However, remember that the teenager should understand when "no" is "no". Avoid bringing up a compromise every time you disagree on something. This might teach him that he can always get away with what he wants, whenever he wants it.

    If the conversation launches into an argument, stop it. Tell him that you both need to calm down and think clearly or the problem will never be solved. If he refuses to listen and continues arguing, step out of the room and allow time for both of you to settle down. Do not scold him or shout back. Your words will possibly be lost on the teenager since you both are too angry to listen to each other. {#blank#}5{#/blank#}

A. He still needs to learn, and he doesn't know everything.

B. Avoid having a bad tone, including accusations in your words.

C. Find the good points the teenager has and mention the negative points too.

D. This article tells you how to disagree with a teenager in a kind manner.

E. People like being listened to, so give him the chance to express his opinion.

F. Come up with a compromise if the situation allows one.

G. Bring up the topic after a while and make sure you listen to each other patiently.