1 . Can we humans avoid war? Can war be prevented ?

    1    . Throughout the ages, from the Stone Age to the Atomic Age, men     have been fighting, first with swords and shields, then with pins and cannous, and now,hydrogen bombs and missiles are used for military purpose. But, in spite of all these. it is still belief that war can prevented and prace can be won, but it requires the effort of every one of us.

    2    If it ever happens, two - thirds of the world and much of the civilization which men have gained   through time,patience and effort will be destroyed.Will then the remaining one - third of the world be able to   survive on its own?

Our task now is not to blame the past，but to plan for the future.

If there is peace in the world, men can use their rockets to explore the mystery of space,their submarines to explore the depth of the sea,their missiles to deliver to mails and their fine equipment to penetrate(穿透）jungles of Africa ,instead of using them military.

Governments can use their money to build more schools,so that more children can be educated to be useful citizens.    3    , They can also design new machines to increase the production of goods and thus improve the way of the people.

    4    It requires,in my opinion,the understanding and friendship be-tween all people from all nations.Let no one suffer discrimination by reason of color,race,reli-gion,or national origin.Let the rich support the poor and the strong help the weak.

We know that neither peace nor such a dream world can come true in a day or month.    5    .But let us plan and begin now.

2 . What happens when you want to go from one place to another, but there's water in the way？That's the problem people faced for hundreds of years in the area that is now New York City. In the city, there is a natural canal called the Narrows, separating Brooklyn on one side from Staten Island on the other.

But the Narrows isn't really so narrow. The water is almost a mile wide, and it's more than 100 feet deep.     1     When they wanted to talk to each other, they climbed into their boats and sailed across.

By the late 1800s, circumstances had changed dramatically. Population growth meant there were now many people needing to travel between Staten Island and Brooklyn for work.     2    

Between 1888 and 1920 there were two major efforts to build a train tunnel to connect the areas.     3     Proposals to build a connecting bridge made during the 1910s also ended in failure due to opposition from the US Navy.

Finally, after World War II, there were so many people living in New York City that leaders decided Brooklyn and Staten Island needed a direct connection. Since tunnels were too expensive, they decided to build a bridge. The design selected had two separate roadways stacked on top of each other.     4     Construction, which took five years, was completed in 1964 and cost $320 million. Today about 190,000 cars and trucks cross the bridge every day.

    5     But in the case of the Narrows, figuring out a good solution took hundreds of years.

3 . It is sometimes thought that the longing for material goods, the need to buy things, is a relatively modern invention.     1     Trade or shopping is certainly an ancient desire, and existed before our ancestors invented writing, laws, cities or farming, even before they used metal to make tools.

Humans are born to trade.     2     Evidence from hunter-gatherers suggests that the exchange of food and other necessary things comes naturally, as well as the ability to keep a record of the credits involved. And once trade begins, the benefits are hard to resist.

Ancient local coastal people in northern Australia traded fish hooks, along a chain of trading partners, with people living 400 miles inland, who cut and polished local stone to make axes (斧子).     3     Finally, both groups of “producers”, by concentrating on things they could produce and exchanging them for other things they needed, benefited as a result.

Trade in the necessities of life, such as food and simple tools, is not really surprising, considering the link between these basic items and survival. What is surprising, though, is that our taste for unnecessary expensive objects also goes back a long way.

In South Africa, 100,000-year-old decorative dyes (染料) have been found in an area where none were produced.     4     Small round pieces of glass 76,000 years old were also found at the same place. The earliest jewellery known to us were not just random findings — they were grouped together in size and had holes like those used for threading onto a necklace.

Archaeologists argue that trade prepared the way for the complex societies in which we live today.     5     However, their modern equivalents — fast cars and expensive clothes — hold the same attraction for us as “trade goods” did for people 100,000 years ago.