Miss Kate taught physics in a New York school. Last month she was explaining to one of her classes about sound, and she decided to test them to see how well they had understood her explanation. She said to them, "Now, I have a brother in Los Angeles. If I was calling him on the phone, and at the same time you were 80 meters away, and were listening to me from across the street, which of you would hear what I said earlier, my brother or you and for what reason?"

A boy at once answered, " Your brother, Miss Kate, because electricity travels faster than sound waves(声波).

"That's very good." Miss Kate said, but then Jenny said, "I don't agree. Your brother would hear you earlier because it is 11 o'clock here, it's only eight o'clock in Los Angeles."

   Red squirrels used to be a common sight in British forests and countryside. But there are fewer than 140,000 red squirrels left now and most of them are in Scotland. However, grey squirrels (introduced from North America) are now so common that many people dislike them. They can be legally（合法的）trapped and destroyed.

   On first sight, the two types of squirrel are similar. They both have a long tail, which helps the squirrel to balance when jumping from tree to tree, and the same large eyes, small ears and powerful back legs. However, the grey squirrel has a clear physical advantage over the red. The red squirrel has a head-and-body length of 19 to 23 centimeters, a tail length of 15 to 20 centimeters and a body weight of 250 to 340 grams. Compared to this, the grey squirrel is a larger animal. The head and body measures between 23 and 30 centimeters long and the tail is between 19 and 25 centimeters long. Adult grey squirrels are heavier, weighing between 400 and 600 grams. This size allows them to store more fat and helps them to survive a hard winter, which would be fatal（致命的）to their  smaller cousins .

So why are red squirrels losing out in competition with grey squirrels? Size is one factor, but there are others. Red squirrels live high up in trees, while grey squirrels spend more of their time on the ground. This means any loss of forests greatly influences the red squirrel population. Another reason for the grey squirrel's success is its ability to use food provided by people. Like the fox, the grey squirrel can survive in towns and cities. The other problem for the red squirrel is disease. Both squirrels carry a certain virus. While this doesn't seem to attack grey squirrels, it is fatal to red squirrels.

阅读理解

    Water is a liquid (液体) ; but it can also be a solid when it is very cold and turns to ice. It can also be a gas, when it evaporates (蒸发) and become water vapour (水蒸气) .

The water cycle

    Water is very important, and without it life on Earth would be impossible. The oceans that cover three quarters of the Earth's surface can be thought of as our great water reservoirs. All the time, water is being evaporated from the ocean's surface by the warmth of the sun. High in the sky this water vapour, turns into clouds which drift (漂浮) over the land, often creating rainfall. As the rain falls,it seeps (渗漏) into the soil and then into rivers that flow back into the oceans, where it is ready to begin all over again!

下面是被打乱的有关The water cycle（水循环）的信息，请根据短文内容重新排序。首句己给出：

Water is warmed by the sun and turns into water vapour and rises into the sky.

Information Card

    The Silk Road is known all over the world.{#blank#}1{#/blank#}It went along the north of China, India, and Persia and ended up in Eastern Europe near today's Turkey and the Mediterranean Sea.

    It was called the Silk Road because one of the major products traded was silk cloth from China. Chinese silk was soft and of high quality. So people throughout Asia and Europe loved it very much.{#blank#}2{#/blank#}Even the Romans called China the "land of silk".

    Besides silk, the Chinese also sold tea, salt, sugar, porcelain(瓷器)and spices(香料). Most of the goods were expensive. This was because it was a long trip and trades didn't have a lot of room for goods. They bought goods like cotton, ivory, wool, gold and silver.

    Traders traveled in large caravans (商队). They would have many guards with them.{#blank#}3{#/blank#}Most of the road was through dry land, so camels were popular animals for transport.

    Although there was some trade between China and the rest of the world for some time, the silk trade developed quickly during the Han Dynasty which ruled from 206 B. C. to 220 A.D.{#blank#}4{#/blank#}During this time, Chinese traders traveled safely. Also, traders had a higher social position.

    {#blank#}5{#/blank#}It not only helped develop trade between different countries, but also helped make ideas, cultures and inventions spread across the world.

    Everyone needs friends. Friends play a very important role in our lives.{#blank#}1{#/blank#} Some of our friendships are not very helpful. Here are some opinions of what truly successful friendships are like.

    {#blank#}2{#/blank#} They share the same sense of humor(幽默). It's what helps their relation keep so strong. Best friends cheer each other on no matter where they are in life.{#blank#}3{#/blank#} And they comfort each other when something terrible happens. They want to be successful together，so they try to help each other out as much as possible.

    True friends value honesty. They talk about something directly.{#blank#}4{#/blank#} If there's a disagreement, they talk it out in person. They make sure to communicate as openly and honestly as possible, because they know that's how real friendships last.{#blank#}5{#/blank#} They don't wish their friend would change(改变) this or that. They just know who they are，and they accept(接受) their friend completely.