1 . 阅读下面短文，在空白处填入1个适当的单词或括号内单词的正确形式。

Who built the first canal? Perhaps some people long ago, living in       1     dry country,discovered that they could dig ditches(沟壑)     2    (irrigate) their fields with the river water. And naturally in the days     3    boats were the most important means of transport, canals were the easiest means of reaching a place. Furthermore,a ditch     4     (join) two rivers proved efficient for boat travel.

Today, most countries in the world have canals. Even in the 2lst century, goods can be moved more     5    (convenient) by boat than by some other means of transport. Some canals, such as the Suez or the Panama,     6     (save) ships weeks of time by making their voyage a thousand miles     7    (short). Other canals permit boats to reach cities that     8    (situate) inland. Still other canals drain lands where there is too much water. Help farmers irrigate fields without enough water, and provide water power for     9     (factory) as well.

Most of the canals have a long history. Canals existed in Egypt thousands of years ago. And the Grand Canal of China was begun about 2,500 years ago. and took centuries to finish. During the seventeenth century, France built many canals that are still     10    use today.

2 . By the end of the century, if not sooner, the world’s oceans will be bluer and greener thanks to a warming climate, according to a new study.

At the heart of the phenomenon lie tiny marine microorganisms(海洋微生物) called phytoplankton. Because of the way light reflects off the organisms, these phytoplankton create colourful patterns at the ocean surface. Ocean colour varies from green to blue, depending on the type and concentration of phytoplankton. Climate change will fuel the growth of phytoplankton in some areas, while reducing it in other spots, leading to changes in the ocean’s appearance.

Phytoplankton live at the ocean surface, where they pull carbon dioxide(二氧化碳) into the ocean while giving off oxygen. When these organisms die, they bury carbon in the deep ocean, an important process that helps to regulate the global climate. But phytoplankton are vulnerable to the ocean’s warming trend. Warming changes key characteristics of the ocean and can affect phytoplankton growth, since they need not only sunlight and carbon dioxide to grow, but also nutrients.

Stephanie Dutkiewicz, a scientist in MIT’s Center for Global Change Science, built a climate model that projects changes to the oceans throughout the century. In a world that warms up by 3℃, it found that multiple changes to the colour of the oceans would occur. The model projects that currently blue areas with little phytoplankton could become even bluer. But in some waters, such as those of the Arctic, a warming will make conditions riper for phytoplankton, and these areas will turn greener. “Not only are the quantities of phytoplankton in the ocean changing. ” she said, “but the type of phytoplankton is changing.”

And why does that matter? Phytoplankton are the base of the food web. If certain kinds begin to disappear from the ocean, Dutkiewicz said, “it will change the type of fish that will be able to survive.” Those kinds of changes could affect the food chain.

Whatever colour changes the ocean experiences in the coming decades will probably be too gradual and unnoticeable, but they could mean significant changes. “It’ll be a while before we can statistically show that the changes are happening because of climate change,” Dutkiewicz said, “but the change in the colour of the ocean will be one of the early warning signals that we really have changed our planet.”

1. What are the first two paragraphs mainly about?

A．The various patterns at the ocean surface.

B．The cause of the changes in ocean colour.

C．The way light reflects off marine organisms.

D．The efforts to fuel the growth of phytoplankton.

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

A．Sensitive.

B．Beneficial.

C．Significant.

D．Unnoticeable.

3. What can we learn from the passage?

A．Phytoplankton play a declining role in the marine ecosystem.

B．Dutkiewicz’s model aims to project phytoplankton changes.

C．Phytoplankton have been used to control global climate.

D．Oceans with more phytoplankton may appear greener.

4. What is the main purpose of the passage?

A．To assess the consequences of ocean colour changes.

B．To analyse the composition of the ocean food chain.

C．To explain the effects of climate change on oceans.

D．To introduce a new method to study phytoplankton.

3 . An extremely enthusiastic truth seeker who runs the YouTube channel Bright Insight claims（声称）to have found the mysterious city of Atlantis and insists that its true location has been hiding in plain sight for thousands of years.

In a video, YouTube blogger Jimmy Bright argues that the Richat Structure, a geologic dome（穹状物）in northwest Sahara also referred to as the Eye of the Sahara, is the most likely location of Atlantis.

He mentioned measurements from the famous Dialogues of Plato, which gave birth to the mystery. The Greek philosopher（哲学家）claimed that Atlantis was a long-gone kingdom, which stretched into Europe as far as Italy and into Africa as far as Egypt thousands of years ago. The giant island was said to be wiped off the face of the planet by a natural disaster“in a single day and night of misfortune”.

At first sight, this has nothing to do with the land-based Richat Structure, but Jimmy claims that the so-called Younger Dryas theory could be a possible explanation. According to it, a massive change in global temperatures caused unexpected climate change and sea level to rise.

In what can be viewed as another proof to the Sahara theory, the diameter（直径）of the Richat Structure’s outer circle is 23.5 km according to Google Map’s measurements, which matches those mentioned by Plato — 127 stadia, which is roughly 23.5 km in today’s terms.

Another thing that helps solve the mystery is a theory that the Eye of the Sahara closely matches the description from Plato’s dialogues. The ancient philosopher wrote that the main city of Atlantis consisted of circles of water and land, which, Jimmy said, looks very similar to the circular form of the Richat Structure.

Although the majority of researchers believe that Plato’s story was nothing but a moral story used to describe a failed idea of seeking power and searching for fortune, it has raised quite a few theories, Since the Middle Ages, explorers have been pointing fingers at different places around the world, including the Atlantic Ocean and the Mediterranean Sea, with the most amazing theories linking the location of Atlantis to the Antarctic and the North Sea.

1. What does Jimmy Bright claim to have discovered?

A．The most likely location of Atlantis.

B．The formation of the Richat Structure.

C．The measurements in the Dialogues of Plato.

D．The reasons behind the Younger Dryas theory.

2. How did Jimmy Bright do research into the location of Atlantis and arrive at a conclusion?

A．By studying the history of ancient Egypt.

B．By analyzing the research into Plato’s life story.

C．By explaining the Younger Dryas theory in a scientific way.

D．By comparing the Richat Structure with the famous Dialogues of Plato.

3. What’s the purpose of mentioning the Younger Dryas theory in Paragraph 4?

A．To stress the importance of the Richat Structure.

B．To present the influence it had on Atlantis.

C．To prove that Jimmy Bright might be correct.

D．To show Jimmy Bright’s opinion is unique.

4. What can be learned from the article?

A．The Eye of the Sahara is a mystery mentioned in the Dialogues of Plato.

B．The Richat Structure is where the mysterious city of Atlantis used to lie.

C．The Younger Dryas may have caused the disappearance of Atlantis overnight.

D．The Plato’s Story is meant to inspire explorers to locate the exact position of Atlantis.