In modern society, people use money every day. It seems that it is very important in our life. That’s because without money you can’t buy any goods(商品) you want. But I think few people know the history of money.
Long ago, people did not need money. They lived on wild animals, fruits and other plants. As time passed, people learned to raise animals and crops. Sometimes, families produced more than they needed, so they started to trade with other families. Later, people began to use money as a means of exchange. However, it was not the kind of money we use today. They used shells, rice, salt, large stones, etc.
During the 600s BC, people began using coins as money. They soon found that coins were easier to carry than goods and lasted a long time. Later, countries began to make their own coins.
The Chinese were the first to use paper money, probably as early as the 11^th century. The Italian traveler Marco Polo saw the Chinese using money when he visited China in the 1200s. However, European countries did not start using paper money until 1600s.
Today, we have many ways to pay for things. We do not use coins or paper money. Often, people prefer to pay for things by card. Paying with a card is easier and safer than carrying around a lot of “real” money.
【小题1】  People used ________ as a means of exchange before the 7^th century BC.
A. paper money       B. card          
C. large stone         D. coins
【小题2】From the passage, we know that European countries used paper money in the ________.

Hundreds of years ago, life was much harder than it is today．People didn’t have modern machines．There was no modern medicine, either．

Life today has brought new problems．One of the biggest is pollution．Water pollution has made our rivers and lakes dirty．It kills our fish and pollutes our drinking water．Noise pollution makes us talk louder and become angry more easily．Air pollution is the most serious kind of pollution．It’s bad to all living things in the world．

Cars, planes and factories all pollute our air every day．Sometimes the polluted air is so thick that it is like a quilt over a city．This kind of quilt is called smog．

Many countries are making rules to flight pollution．Factories must now clean their water before it is thrown away and they mustn’t blow dirty smoke into the air

We need to do many other things．We can put waste things in the dustbin and do not throw them on the ground，there will be less pollution．

Rules are not enough．Every person must help to fight pollution．

1.Hundreds of years ago．life was much harder than it is today because        ．

2.The most serious kind of pollution is         ．

3.From the passage we know that       ．