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 three main 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 “135520135.”

    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.

How to Be Healthy and Happy

    We all want to be healthy, happy, free of stress and more productive in life.

    ⒈Get enough sleep. It not only keeps you healthy but also you will be happier. It is said that “Early to bed, early to rise makes a man healthy, wealthy and wise.”{#blank#}1{#/blank#}

    ⒉Drink plenty of water. {#blank#}2{#/blank#} The benefits of water are amazing. Water helps keep your skin clear, leaving you feeling happier and better about your body. Water is just simply an amazing source in itself for your overall health. Try to drink 8 glasses a day.

    ⒊Smile and laugh. Don't get sad over small problems or take any joke seriously which hurt you. Instead, if you feel so hurt, you prefer to stay away from that friend. {#blank#}3{#/blank#} Respect your friend from a good perspective. Smile and laugh all the time and you will be happy.

    ⒋{#blank#}4{#/blank#}Help your mom do the dishes, help out your dad in the kitchen, clean your room, or do anything that could help your family. It will not only make them love you more, but you will feel happy knowing you have done good even if you moved out twenty years ago and are a father yourself.

    ⒌Have goals. Always believe you can achieve. If you can dream it, you can achieve it, no matter what. {#blank#}5{#/blank#} Organization plays a very important role in achieving goals, so organize yourself.

New Reasons to Exercise

    It's a cruel reality that exercising is not a reliable way to lose weight and keep it off. {#blank#}1{#/blank#} Here are the benefits of regular exercise.

    {#blank#}2{#/blank#}

    A new study had found that just a short period of exercise can help improve the ability to remember things in the hours that follow. The report says, “Exercising four hours after learning a task can help people remember that task in the long term”

    It may keep off depression.

    {#blank#}3{#/blank#} Researchers found that women who exercised regularly reported about 50% fewer depressive signs than women who didn't exercise as much. And the more the women reported exercising, the less likely they were to have signs of depression.

    It can control appetite.(食欲)

    Exercise may be the key to controlling your appetite . A study found that people who exercised for 15 minutes after doing mental work ate 100 fewer calories than people who did mental work and then remained seated. Exercise has the ability to increase available fuel sources in the body that may signal to the brain. “{#blank#}4{#/blank#}I don't need to fill myself with food,” says study author William H. Neumeirer.

    It increases energy.

    In a recent report, men who cycled for 20 minutes experienced a 166% increase in self-reported energy levels, compared with a 15% increase when they sat and did nothing for the same amount of time.{#blank#}5{#/blank#}

A.It improves memory.

B.It has mind-body benefits.

C.Here is the energy source I need.

D.We do the work at the office each day.

E.Working out regularly might prevent depression.

F.But that doesn't mean you should give up the effort.

G.If you need a reason to work out, energy increase is a worthwhile one.

Ways to Worry Less

    Do you want to worry less? Of course you do. That's like asking if I can send you free bacon. Worry is like black mold—it appears in damp conditions and spreads uncontrollably. And very often we don't realize it's there until it's killing us. We must get rid of worry before it destroys us. But how should we do it? {#blank#}1{#/blank#}

    Do what you need to do.

    {#blank#}2{#/blank#} You ought not to avoid tough projects or hard conversations. If you don't do what you should be doing, you will end up spending the rest of the time worrying about the must-do things. Believe it or not, the anxiety that comes from the worry is much worse than the task we're worried about.

    {#blank#}3{#/blank#}

    I think many of us act like we're puppets (木偶) in a play and we're waiting for something or someone to put us in the right place. We just react to whatever is going on. {#blank#}4{#/blank#} We need to live purposefully. Nothing can cause more worry than purposelessness.

    Make plans.

    You can't succeed without making plans. Making plans will enable you to achieve your aims more smoothly. However, your plans aren't set in stone. You can adjust your plans flexibly. Accept changes. {#blank#}5{#/blank#}

    There are other ways to lessen worry. As long as you are determined to take action, you will live a worry-free life.

    Really organized people are not born organized people.{#blank#}1{#/blank#} ,which then help them stay organized. Here are four habits they use to keep their lives in order.

    Write things down. A pen and a notebook are needed to record things. {#blank#}2{#/blank#} .You will only further make your life complex(复杂的) by trying to contain important dates and messages in your head.

    Make schedules and deadlines. By leading a cluttered(杂乱的) lifestyle, you will not have the time or space to make your deadlines or achieve your goals. Organized people don't waste time.

    They recognize that keeping things organized goes hand in hand with staying productive(富有成效的). They make and keep schedules for the day and week. They make deadlines and set goals.{#blank#}3{#/blank#}.

    Don't put off doing what you should be doing .{#blank#}4{#/blank#}.If you want your life to be less stressful, then take action as soon as you can. Put in effort to get things done as soon as possible.

    {#blank#}5{#/blank#}.People who live organized lives only keep what they need and what they really want .Have you ever felt like you don't have the space to keep all the things you own? Instead of buying a larger house, get rid of some.

A. Give everything a home

B. Keep only what you need

C  They have to develop some habits

D. And most importantly, they stick to them.

E. You can also use a computer or a smart phone

F. Organized people find time every week to organize their things

G. The longer you wait to do something, the more difficult it will be to get it done

    I don't believe Artificial Intelligence (AI) could replace my teaching career. I have always been interested in human connection, and the ways in which I can use these connections to inspire change and make a difference. {#blank#}1{#/blank#}, there are other ways where AI could make a more efficient and effective difference than I could on my own.

    My teaching experiences over the past several years have been creative and inspiring. I believe that the job of educators extends beyond simply teaching students a set curriculum. {#blank#}2{#/blank#}, they must constantly reflect on ways to better their teaching, and they must inspire their students to be the best versions of themselves. And now with the help AI, they could achieve these goals much easier.

    {#blank#}3{#/blank#}. First, AI can be used to promote fundamental skills, such as mathematical education and vocabulary lessons. Additionally, I see AI being used for such necessary tasks as answering questions and grading assignments. Thus I could focus my attention to establishing human connection, individualizing lesson plans and inspiring my students.

    {#blank#}4{#/blank#}. I believe AI could provide a strong basis for educational equality around the world. According to Todd Leopold, close to 800 million people worldwide are functionally illiterate (不识字的). Due to its ability to efficiently pass knowledge across large groups of people fewer teachers may be needed in some schools. {#blank#}5{#/blank#}.

A. Since students will always need a human teacher

B. The benefit AI brings is far beyond my own classroom

C. I think AI is a powerful assistant to my future classroom

D. The need for students to learn how to use AI will also grow

E. Although human connection may never be able to be fully replaced by AI

F. This could be an opportunity for students everywhere to receive equal education

G. They must observe and get to know their students in order to individualize educational plans