2 . Frozen in time, a 125-million-year-old mammal attacking a dinosaur. A 39-million-year-old whale, the heaviest animal that ever lived. The oldest known jellyfish, from 505 million years ago. Paleontology (古生物学) produces newsworthy discoveries.

Fossils (化石), moreover, provide direct evidence for the long history of life, allowing paleontologists to test hypotheses (假设) about evolution with data only they provide. They allow investigation of present and past life on Earth. Flows of biological diversity, appearances of new life forms and the extinctions of long existing ones, would go undiscovered without these efforts. But the headlines over exciting new fossils greatly underestimate the true importance of paleontology. Its real significance lies in how such discoveries brighten the grand history of life on Earth. From its beginnings, more than three billion years ago, to the present day, fossils record how life adapted or disappeared in the face of major environmental challenges.

Paleontologists provide us with a unique vantage on modern climate change. They play an essential role in interpreting ancient environments, in reconstructing ancient oceans, continents and climates. Fossils provide key limitation on the climate models that are essential for predicting future climate change. And the fossil record gives important insights into how life will respond to predicted future climate conditions, because these have occurred before in Earth’s history.

In addition, paleontology has provided a fundamental contribution to human thought: the reality of species extinction and thus of a world that has dramatically changed over time. In documenting the history of life, paleontologists recognized that many extinction episodes could occur suddenly, such as the event 66 million years ago that ended the dinosaurs. The search for the causes of past mass extinctions started pioneering studies from across the scientific spectrum (科学界), focusing on potential future threats to humanity.

Not only do paleontologists know what happens to life when things go bad, they also know how long it takes for ecosystems and biodiversity to recover from these disasters, which can take far longer than modern humans have existed.

Paleontologists thus provide a unique perspective on the nature and future long-term ecological impact of the current human-produced biodiversity crisis, the so-called Sixth Extinction, and therefore the importance of protecting modern biodiversity. The very concept of a Sixth Extinction would not exist without paleontologists documenting the first five.

Paleontologists know that understanding life’s past is critical to anticipating and adapting to life’s and humanity’s future. Paleontology is important because it brings its unique and critical perspective to current challenges in climate change, biodiversity loss and the environment. Paleontologists can predict the future because they know the past.

1. The first two paragraphs are written to _______.

A．describe an event	B．raise a question
C．present an opinion	D．make a comparison

2. What does the underlined word “vantage” in Paragraph 3 mean?

A．A positive effect.	B．A valuable suggestion.
C．A quick decision.	D．A comprehensive view.

3. Which of the following would the author agree with?

A．Ecological recovery takes shorter than imagined.

B．Past lessons can help to predict the future threats.

C．Paleontologists can handle the biodiversity crisis.

D．Fossil studies focus on the causes of mass extinctions.

4. What’s the best title for the passage?

A．Paleontology: A Pioneering Study

B．Paleontology: A History Recorder

C．Paleontology Tells More About Nature Than Humans

D．Paleontology Is Far More Than New Fossil Discoveries

3 . Who Invented Silk?

Silk is a thin, yet extremely strong, fiber. It is made from protein that silkworms produce when they make their cocoons. Thousands of years ago, ancient Chinese craftsmen began weaving silk fiber into a soft, smooth fabric. A precious textile, silk was at first reserved for exclusive use by the Chinese imperial court. Chinese officials decided that silk-making methods must remain China’s secret.     1    

The Silky Secret Gets Out

However, the existence of silk did not remain a secret. On diplomatic visits to neighboring rulers, Chinese envoys carried gifts of silk. By the first century BC, the Romans had become familiar with this exotic(异国情调的)luxury item.     2     Western rulers issued edicts (法令)that controlled silk prices. As in China, silk was designated a solely royal fabric. Trading for silk was principal motivation for merchants who searched for routes.

From Europe to the Far East

Over the centuries, different main routes developed.     3     Tradesmen travelling east or west could choose among routes that crossed many regions of Eastern Europe, the Middle East, Central Asia, and the Far East.     4     Trading vessels carried goods from China and Southeast Asia across Indian Ocean to Africa, India, and the Near East. Sea routes even reached Venice, Italy, by crossing the Mediterranean.

    5    

The Silk Road played an important role in bringing diverse cultures and peoples into contact. To make successful deals, merchants had to learn the languages and customs of the countries they crossed. As they journeyed along the Silk Road, people shared knowledge about arts, crafts, literature, science, and technologies. Over hundreds of years, cultures, languages, and religions influenced one another. Perhaps Chinese silk influenced history more extensively than any single famous person you can name.

A．How Silk Changed History

B．How Silk Brought People Together

C．It soon grew wildly popular in the West.

D．In addition, sailors discovered sea routes.

E．Rulers ordered that anyone who revealed these methods to foreigners would be put to death.

F．Later they came to be known as “The Silk Road”, but the word “Road” should have been plural.

G．But, there were many roads, not just one. A German geologist named the trade routes “The Silk Road”.