Long, long ago there lived an old man. He had a very big orange tree in his garden. On the tree there were many fine oranges.

    One day the old man found one of the oranges was bigger than the others. It was as big as a watermelon. So he took the big orange to the king. The king was very happy and gave the old man a lot of money for it.

    When a rich man heard of this, he said to himself, "It is only an orange. Why did the king give him so much money? If I take my gold cup to the king, he will give me much more money for it."

    The next day when the king got the gold cup, he said to the rich man,"What a beautiful cup! I'll give you something for it. Please take the great orange."

    Billy Smith loves water. His hobbies are swimming and diving (潜水). And he likes golf too. Billy's a very lucky man because his interests are part of his job.

    Billy lives in the USA with his wife, Linda. They got married ten years ago. At that time, Billy worked in an office in New York. He worked with computers. He worked five days a week, from eight in the morning to seven in the evening. He hated his job. There was no time for diving or golf. Linda worked in a shop and she didn't like her boss (老板). She hated the cold winters in New York too. So Billy and Linda decided to leave their jobs in New York and buy a house in Florida. The weather is fantastic in Florida. The days are sunny and hot.

    Now Billy goes diving every day and he goes to golf courses (球场) every day. But he doesn't play golf very much—he works at the golf course. He travels around Florida and he goes to lots of different golf courses. Sometimes Linda goes with him and sometimes she stays at home. There are lakes on many golf courses and Billy only goes to golf courses with lakes. Players often hit their golf balls into the water.

    In his new job, Billy dives in the lakes for these golf balls. On some days, Billy collects two thousand golf balls. Linda has an office in their home and she works there. She sells the lost golf balls that Billy finds. For golfers, they are cheaper than new golf balls.

    Both Billy and Linda are very happy now.

根据材料内容简要回答下列问题。

A. It is very hard to break a code without the code book.

B. Only people who know the keyword can read the message.

C. As long as there have been codes, people have tried to break them.

D. You can hide a message by having the first letters of each word spell it out.

E. With a code book, you might write down words that would stand for other words.

F. Another way to hide a message is to use symbols to stand for specific letters of the alphabet.

    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 "13, 5, 5, 20, 15, 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.

    ①Life in the future will be different from life today.

    But what will life be like in the future? The population(人口)is growing  A  . There will be many people in the world and most of them will live to over 100 years old. Computers will be very  B  and useful, and there will be computers in every home. Traveling will be very cheap and  C  .

    And many people will go to other countries for holidays. There will be changes in our food, too. There will not be________(many)room for cows and sheep, so meat will be very expensive. ②也许没有人会每天都吃它。They will eat many fruits and vegetables. Maybe people will be quite healthy. Work in the future will be different, too. Robots will do hard work. So many people will not have enough work to do.

In China, each year we produce about 150 million tons of city waste according to a report. Where does the waste go? People usually burn or bury it. Besides, we receive waste from some developed countries. {#blank#}1{#/blank#}, What about the useless part? Still burned or buried. But is it a proper way?

Waste pollutes the environment, harms people's health and causes animals to die. {#blank#}2{#/blank#}. We can't make money at the cost of the environment. We should leave clean water and green mountains to our next generations (一代人).

China is getting really serious about waste now. We are taking less waste from developed countries. From January 2018, China started to stop 24 kinds of waste coming into our country. And more laws and rules about dealing with waste have been made. {#blank#}3{#/blank#}. China also tries to put waste into good use. One example is the waste electricity factories. {#blank#}4{#/blank#}, No harmful gases or water will get into the environment.

{#blank#}5{#/blank#}.Cities like Shanghai, Chongqing and Beijing have their own sorting systems. More will join them soon. As President Xi Jinping said during a visit to Shanghai, waste sorting is a new fashion.

Many people know LEGO（乐高）. It is from Denmark， and appeared in the 1950s. In about 1960， people began to make LEGO bricks（积木）using a kind of plastic called ABS. 

However， ABS plastic can't be recycled and it takes a very long time to break down（分解）. That's a big problem. 

There is serious plastic pollution around the world. To help save the earth， LEGO began to make new bricks in 2015. These bricks wouldn't pollute the earth so much. Three years later， the factory began making some LEGO parts， like trees， out of a kind of special plastic. The plastic is made from sugar cane（甘蔗）. 

LEGO is now trying to make bricks out of PET plastic. This kind of plastic can be found in things like bottles and clothing. People can make LEGO bricks out of recycled plastic bottles. The factory is working to find out a way to add color to the bricks—right now they're just white.