Unlike buried treasure and some minerals, fossils are usually not valuable in themselves. However, most of the fossils you find will be of greatest value to you. They will help you learn much about the geologic history of the earth and its inhabitants.

If it were not for fossils, we would have no way of knowing about the animals that once roamed the earth or that once crawled on the bottom of the ancient seas. In fact, we would not even know for sure that there were once seas in some regions if it were not for the many fossils of sea animals that we find there.

You can look at some fossils and see for yourself the shape of the ancient animals. Even if you collect only bits of one kind of fossil, you may still be able to tell what it looked like. Making sense out of fossil bits is a little like working a jigsaw puzzle. Sometimes you will lose pieces, but you can still recognize the picture and even use your imagination to fill in missing details. The habits of ancient sea animals are not so easy to determine. Therefore, scientists study the structure and the habits of similar living animals to learn what the ancient ones must have been like. There are some things, however, that neither the study of fossils nor the study of living animals can tell us. For example, no one knows what colour most ancient sea animals were. Also, since the soft parts disappeared soon after death, many details of their internal structure are unknown. So the pictures of ancient sea creatures (as well as dinosaurs!) are what scientists think the animals looked like. Reconstructing the life of an ancient sea animal on the basis of fossil evidence and the characteristics of similar living animals is a little like relying on circumstantial evidence in court.

1. This passage is mainly about animals that __________.

A. have very tough hides

B. once lived on the earth

C. inhabit the seas of today

D. are becoming extinct

2. With the help of fossils we can __________.

A. reconstruct life of the past

B. predict the future

C. explain the changes of the seasons

D. save some species of animals from extinction

3. Many details of ancient animals are lacking because __________.

A. many species have not been found

B. volcanic disasters have permanently buried many fossils

C.many fossils lie in deep water and cannot be recovered

D. soon after death the soft parts of the body decay

49. To “determine" in the passage is closest in meaning to __________.

A. come across

B. study

C. find out

D. imitate

50. This passage implies that a scientist's evaluation of the past is based on __________.

A. laboratory experiments with live animals

B. a few facts mixed with a lot of opinions

C. predictions made in the past and present

D. field studies of our society

Read the following passage and mark the letter A,B,C or D on your answers sheet to indicate the correct answer to each of the questions.

Generally, in order to be preserved in the fossil record, organisms must possess hard body parts such as shells or bones. Soft, fleshy structures are quickly destroyed by predators or decayed by bacteria. Even hard parts left on the surface for any length of time will be destroyed, therefore, organisms must be buried rapidly to escape destruction by the elements and to be protected against agents of weathering and erosion. Marine organisms thus are better candidates for fossilization than those living on the land because the ocean is typical the site of sedimentation, whereas the land is largely the site of erosion. The beds of ancient lakes were also excellent sites for rapid burial of skeletal remains of freshwater organisms and skeletons of other animals, including those of early humans, Ancient swaps were particularly plentiful with prolific growths of vegetation, which fossilized in abundance. Many animals became trapped in bogs overgrown by vegetation. The environment of the swaps kept bacterial decay to a minimum, which greatly aided in the preservation of plants and animals. The rapidly accumulating sediments in flood plains, deltas, and stream channels buried freshwater organisms, along with other plants and animals that happened to fall into the water.

Only a small traction of all the organisms that have ever lived are preserved as fossils. Normally, the remains of a plant or animal are completely destroyed through predation and decay. Although it seems that fossilization is common for some organisms, for others it is almost impossible. For the most part of, the remains of organisms are recycled in the earth, which is fortunate because otherwise soil and water would soon became depleted of essential nutrients. Also, most of the fossils exposed on Earth’s surface are destroyed by weathering processes. This make for an incomplete fossil record with poor or no representation of certain species. The best fossils are those composed of that form the vast majority of unaltered fossils. Calcite and aragonite also contributed to a substantial number of fossils of certain organisms.

The best fossils are those_______

A. consist of Calcite and aragonite

B. from hard parts of animals or plants 

C. still in the shape of the original animal or plant

D. animals or plants common for fossilization

Read the following passage and mark the letter A,B,C or D on your answers sheet to indicate the correct answer to each of the questions.

Generally, in order to be preserved in the fossil record, organisms must possess hard body parts such as shells or bones. Soft, fleshy structures are quickly destroyed by predators or decayed by bacteria. Even hard parts left on the surface for any length of time will be destroyed, therefore, organisms must be buried rapidly to escape destruction by the elements and to be protected against agents of weathering and erosion. Marine organisms thus are better candidates for fossilization than those living on the land because the ocean is typical the site of sedimentation, whereas the land is largely the site of erosion.

The beds of ancient lakes were also excellent sites for rapid burial of skeletal remains of freshwater organisms and skeletons of other animals, including those of early humans, Ancient swaps were particularly plentiful with prolific growths of vegetation, which fossilized in abundance. Many animals became trapped in bogs overgrown by vegetation. The environment of the swaps kept bacterial decay to a minimum, which greatly aided in the preservation of plants and animals. The rapidly accumulating sediments in flood plains, deltas, and stream channels buried freshwater organisms, along with other plants and animals that happened to fall into the water.

Only a small traction of all the organisms that have ever lived are preserved as fossils. Normally, the remains of a plant or animal are completely destroyed through predation and decay. Although it seems that fossilization is common for some organisms, for others it is almost impossible. For the most part of, the remains of organisms are recycled in the earth, which is fortunate because otherwise soil and water would soon became depleted of essential nutrients. Also, most of the fossils exposed on Earth’s surface are destroyed by weathering processes. This make for an incomplete fossil record with poor or no representation of certain species. The best fossils are those composed of that form the vast majority of unaltered fossils. Calcite and aragonite also contributed to a substantial number of fossils of certain organisms.

he best fossils are those                                

A. consist of Calcite and aragonite

B. from hard parts of animals or plants

C.  still in the shape of the original animal or plant

D. animals or plants common for fossilization

Read the following passage and mark the letter A,B,C or D on your answers sheet to indicate the correct answer to each of the questions.

Generally, in order to be preserved in the fossil record, organisms must possess hard body parts such as shells or bones. Soft, fleshy structures are quickly destroyed by predators or decayed by bacteria. Even hard parts left on the surface for any length of time will be destroyed, therefore, organisms must be buried rapidly to escape destruction by the elements and to be protected against agents of weathering and erosion. Marine organisms thus are better candidates for fossilization than those living on the land because the ocean is typical the site of sedimentation, whereas the land is largely the site of erosion.

The beds of ancient lakes were also excellent sites for rapid burial of skeletal remains of freshwater organisms and skeletons of other animals, including those of early humans, Ancient swaps were particularly plentiful with prolific growths of vegetation, which fossilized in abundance. Many animals became trapped in bogs overgrown by vegetation. The environment of the swaps kept bacterial decay to a minimum, which greatly aided in the preservation of plants and animals. The rapidly accumulating sediments in flood plains, deltas, and stream channels buried freshwater organisms, along with other plants and animals that happened to fall into the water.

Only a small traction of all the organisms that have ever lived are preserved as fossils. Normally, the remains of a plant or animal are completely destroyed through predation and decay. Although it seems that fossilization is common for some organisms, for others it is almost impossible. For the most part of, the remains of organisms are recycled in the earth, which is fortunate because otherwise soil and water would soon became depleted of essential nutrients. Also, most of the fossils exposed on Earth’s surface are destroyed by weathering processes. This make for an incomplete fossil record with poor or no representation of certain species. The best fossils are those composed of that form the vast majority of unaltered fossils. Calcite and aragonite also contributed to a substantial number of fossils of certain organisms.

According to the passage, an organisms without hard body parts   

A. is not heavy enough to sink below the surface

B. is not attractive to predators

C. is not likely to appear in the fossil record

D. takes a long time to decay

Read the following passage and mark the letter A,B,C or D on your answers sheet to indicate the correct answer to each of the questions.

Generally, in order to be preserved in the fossil record, organisms must possess hard body parts such as shells or bones. Soft, fleshy structures are quickly destroyed by predators or decayed by bacteria. Even hard parts left on the surface for any length of time will be destroyed, therefore, organisms must be buried rapidly to escape destruction by the elements and to be protected against agents of weathering and erosion. Marine organisms thus are better candidates for fossilization than those living on the land because the ocean is typical the site of sedimentation, whereas the land is largely the site of erosion.

The beds of ancient lakes were also excellent sites for rapid burial of skeletal remains of freshwater organisms and skeletons of other animals, including those of early humans, Ancient swaps were particularly plentiful with prolific growths of vegetation, which fossilized in abundance. Many animals became trapped in bogs overgrown by vegetation. The environment of the swaps kept bacterial decay to a minimum, which greatly aided in the preservation of plants and animals. The rapidly accumulating sediments in flood plains, deltas, and stream channels buried freshwater organisms, along with other plants and animals that happened to fall into the water.

Only a small traction of all the organisms that have ever lived are preserved as fossils. Normally, the remains of a plant or animal are completely destroyed through predation and decay. Although it seems that fossilization is common for some organisms, for others it is almost impossible. For the most part of, the remains of organisms are recycled in the earth, which is fortunate because otherwise soil and water would soon became depleted of essential nutrients. Also, most of the fossils exposed on Earth’s surface are destroyed by weathering processes. This make for an incomplete fossil record with poor or no representation of certain species. The best fossils are those composed of that form the vast majority of unaltered fossils. Calcite and aragonite also contributed to a substantial number of fossils of certain organisms.

It can be inferred that flood plains, deltas, and stream channels are similar in which of the following ways?

A. Rapid sedimentation in such locations makes it difficult to locate fossils.

B. Such locations are likely to rich sources of fossils.

C. Fossilized human remains are only rarely found in such locations

D.  Animals rather than plants have been preserved at such locations.

Read the following passage and mark the letter A,B,C or D on your answers sheet to indicate the correct answer to each of the questions.

Generally, in order to be preserved in the fossil record, organisms must possess hard body parts such as shells or bones. Soft, fleshy structures are quickly destroyed by predators or decayed by bacteria. Even hard parts left on the surface for any length of time will be destroyed, therefore, organisms must be buried rapidly to escape destruction by the elements and to be protected against agents of weathering and erosion. Marine organisms thus are better candidates for fossilization than those living on the land because the ocean is typical the site of sedimentation, whereas the land is largely the site of erosion. The beds of ancient lakes were also excellent sites for rapid burial of skeletal remains of freshwater organisms and skeletons of other animals, including those of early humans, Ancient swaps were particularly plentiful with prolific growths of vegetation, which fossilized in abundance. Many animals became trapped in bogs overgrown by vegetation. The environment of the swaps kept bacterial decay to a minimum, which greatly aided in the preservation of plants and animals. The rapidly accumulating sediments in flood plains, deltas, and stream channels buried freshwater organisms, along with other plants and animals that happened to fall into the water.

Only a small traction of all the organisms that have ever lived are preserved as fossils. Normally, the remains of a plant or animal are completely destroyed through predation and decay. Although it seems that fossilization is common for some organisms, for others it is almost impossible. For the most part of, the remains of organisms are recycled in the earth, which is fortunate because otherwise soil and water would soon became depleted of essential nutrients. Also, most of the fossils exposed on Earth’s surface are destroyed by weathering processes. This make for an incomplete fossil record with poor or no representation of certain species. The best fossils are those composed of that form the vast majority of unaltered fossils. Calcite and aragonite also contributed to a substantial number of fossils of certain organisms.

It can be inferred that flood plains, deltas, and stream channels are similar in which of the following ways?

A. Rapid sedimentation in such locations makes it difficult to locate fossils 

B. Such locations are likely to rich sources of fossils. 

C. Fossilized human remains are only rarely found in such locations 

D. Animals rather than plants have been preserved at such locations.

Read the following passage and mark the letter A,B,C or D on your answers sheet to indicate the correct answer to each of the questions.

Generally, in order to be preserved in the fossil record, organisms must possess hard body parts such as shells or bones. Soft, fleshy structures are quickly destroyed by predators or decayed by bacteria. Even hard parts left on the surface for any length of time will be destroyed, therefore, organisms must be buried rapidly to escape destruction by the elements and to be protected against agents of weathering and erosion. Marine organisms thus are better candidates for fossilization than those living on the land because the ocean is typical the site of sedimentation, whereas the land is largely the site of erosion. The beds of ancient lakes were also excellent sites for rapid burial of skeletal remains of freshwater organisms and skeletons of other animals, including those of early humans, Ancient swaps were particularly plentiful with prolific growths of vegetation, which fossilized in abundance. Many animals became trapped in bogs overgrown by vegetation. The environment of the swaps kept bacterial decay to a minimum, which greatly aided in the preservation of plants and animals. The rapidly accumulating sediments in flood plains, deltas, and stream channels buried freshwater organisms, along with other plants and animals that happened to fall into the water.

Only a small traction of all the organisms that have ever lived are preserved as fossils. Normally, the remains of a plant or animal are completely destroyed through predation and decay. Although it seems that fossilization is common for some organisms, for others it is almost impossible. For the most part of, the remains of organisms are recycled in the earth, which is fortunate because otherwise soil and water would soon became depleted of essential nutrients. Also, most of the fossils exposed on Earth’s surface are destroyed by weathering processes. This make for an incomplete fossil record with poor or no representation of certain species. The best fossils are those composed of that form the vast majority of unaltered fossils. Calcite and aragonite also contributed to a substantial number of fossils of certain organisms.

Why are marine organisms good candidates for fossilization?

A. It take longer for them to be preserved 

B. They have more fleshy structures than land organisms 

C. The water environment speeds the decay caused by bacteria 

D. It is likely that they will be buried rapidly

Read the following passage and mark the letter A,B,C or D on your answers sheet to indicate the correct answer to each of the questions.

Generally, in order to be preserved in the fossil record, organisms must possess hard body parts such as shells or bones. Soft, fleshy structures are quickly destroyed by predators or decayed by bacteria. Even hard parts left on the surface for any length of time will be destroyed, therefore, organisms must be buried rapidly to escape destruction by the elements and to be protected against agents of weathering and erosion. Marine organisms thus are better candidates for fossilization than those living on the land because the ocean is typical the site of sedimentation, whereas the land is largely the site of erosion.

The beds of ancient lakes were also excellent sites for rapid burial of skeletal remains of freshwater organisms and skeletons of other animals, including those of early humans, Ancient swaps were particularly plentiful with prolific growths of vegetation, which fossilized in abundance. Many animals became trapped in bogs overgrown by vegetation. The environment of the swaps kept bacterial decay to a minimum, which greatly aided in the preservation of plants and animals. The rapidly accumulating sediments in flood plains, deltas, and stream channels buried freshwater organisms, along with other plants and animals that happened to fall into the water.

Only a small traction of all the organisms that have ever lived are preserved as fossils. Normally, the remains of a plant or animal are completely destroyed through predation and decay. Although it seems that fossilization is common for some organisms, for others it is almost impossible. For the most part of, the remains of organisms are recycled in the earth, which is fortunate because otherwise soil and water would soon became depleted of essential nutrients. Also, most of the fossils exposed on Earth’s surface are destroyed by weathering processes. This make for an incomplete fossil record with poor or no representation of certain species. The best fossils are those composed of that form the vast majority of unaltered fossils. Calcite and aragonite also contributed to a substantial number of fossils of certain organisms.

Why are marine organisms good candidates for fossilization?

A.  It take longer for them to be preserved

B.  They have more fleshy structures than land organisms

C. The water environment speeds the decay caused by bacteria

D.  It is likely that they will be buried rapidly

Read the following passage and mark the letter A,B,C or D on your answers sheet to indicate the correct answer to each of the questions.

Generally, in order to be preserved in the fossil record, organisms must possess hard body parts such as shells or bones. Soft, fleshy structures are quickly destroyed by predators or decayed by bacteria. Even hard parts left on the surface for any length of time will be destroyed, therefore, organisms must be buried rapidly to escape destruction by the elements and to be protected against agents of weathering and erosion. Marine organisms thus are better candidates for fossilization than those living on the land because the ocean is typical the site of sedimentation, whereas the land is largely the site of erosion.

The beds of ancient lakes were also excellent sites for rapid burial of skeletal remains of freshwater organisms and skeletons of other animals, including those of early humans, Ancient swaps were particularly plentiful with prolific growths of vegetation, which fossilized in abundance. Many animals became trapped in bogs overgrown by vegetation. The environment of the swaps kept bacterial decay to a minimum, which greatly aided in the preservation of plants and animals. The rapidly accumulating sediments in flood plains, deltas, and stream channels buried freshwater organisms, along with other plants and animals that happened to fall into the water.

Only a small traction of all the organisms that have ever lived are preserved as fossils. Normally, the remains of a plant or animal are completely destroyed through predation and decay. Although it seems that fossilization is common for some organisms, for others it is almost impossible. For the most part of, the remains of organisms are recycled in the earth, which is fortunate because otherwise soil and water would soon became depleted of essential nutrients. Also, most of the fossils exposed on Earth’s surface are destroyed by weathering processes. This make for an incomplete fossil record with poor or no representation of certain species. The best fossils are those composed of that form the vast majority of unaltered fossils. Calcite and aragonite also contributed to a substantial number of fossils of certain organisms.

The word “aided ” in the second paragraph is closest in meaning to 

A. counted

B. reformed

C. reversed

D. helped