What are fossils?

Fossils are the remains of plants or animals. For such remains to be considered fossils, scientists have decided they have to be over 10,000 years old. The word fossil comes from the Latin word “fossilis”, which means, “dig up”.  Fossils can be divided into “body fossils” and “trace(痕迹) fossils”. Body fossils are the remains of a plant or animal’s body. Trace fossils are the remains of the activity of an animal, such as footprints, egg shells, and nests.

How are fossils formed?

Some animals were quickly covered after their death by sediment(沉淀物) like earth, mud or sand. Over time, the parts of the animals that didn’t rot (usually the harder parts like bones and teeth) were covered in the newly formed sediment. Then, a lot of chemical changes happened to the animals bodies. Water with minerals(矿物质) went into the bone and took the place of the chemicals in the bone with rock-like minerals. In the end we get a heavy, rock-like copy of the original object - a fossil. There weren’t any changes in size and shape when an object changed into a fossil, but the fossil of a bone doesn’t have any bone in it! It is chemically more like a rock! According to scientists, fossils have been found on every continent(大陆) on Earth.

1.Trace fossils can’t be formed from the ______ of some kind of animals.

A. footprints B. nests C. eggs D. bodies

2.______ brings the rock-like minerals into the bone.

A. Sunlight B. Earth C. Water D. Air

3.According to the last paragraph, the fossil is as ______ as the original object.

A. heavy B. big C. old D. clean

4.We can know that ______ from the passage.

A. scientists think that the fossils may have a history of 100 centuries.

B. people haven’t found any fossil on the continent of Africa.

C. we can find some real bones in the fossils of a bone.

D. there are many kinds of sediment in the fossils.

5.This passage most probably comes from ______.

A. an advertisement B. a medical magazine C. a science book D. a notice

What picture do you have of the future? Will life in the future be better, worse or the same as now? What do you hope for about the future? Scientists think that life will probably be very different in 2050.

First of all, it seems that people won’t use TV channel(频道) by 2050. Instead, people will choose a program from a “menu” and a computer will send the program directly(直接地) to the television.

Water will become a very serious problem. We’ll need much more water, but there won’t be enough. Some scientists think that water would be the cause of war(战争).

Cars will run on new clean energy and they will go very fast. And there won’t be any accidents with the help of computer. On the other hand, space planes will take people around the world in two hours.

Robots will works in the factories instead of people. Many factories have already used robots. Big companies prefer robots---they do not ask for money, and they work for 24 hours a day---

In a word, by 2050, our life will change a lot and our future will be quite different from now.

1.Maybe people won’t use any more by 2050.

A. computers B. TV channels C. robots D. space planes

2.Scientists think will take people around the world in .

A. two seconds B. two days C. two years D. two hours

3.Scientists think that would be cause of war.

A. water B. cars C. robots D. TV channels

4. Will work in big companies and won’t ask for money.

A. Workers B. Cars C. Robots D. People

5.According to the passage, our life in the future will be .

A. good B. better

C. the same D. quite different from now

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