题目内容：

    In the western Pacific Ocean lies the deepest place on the planet — the Mariana Trench, which runs as deep as about 7 miles below the ocean’s surface. That’s greater than the height of Mount Everest measuring about 5 and a half miles above sea level.

The Mariana Trench is home to a variety of sea life. Coral reefs and underwater volcanoes are all found there. But because few humans have been able to go far into the trench, scientists know little about it.

Now they are working to change that. Recently, the Okeanos Explorer has been on an exploration there. Remotely operated vehicles sent out from it are taking videos of life in its deepest, darkest areas. Scientists around the world, along with the general public, can watch the videos in real time. These videos are showing the most mysterious parts of the ocean. Much of the area that the Okeanos Explorer is exploring has been protected since 2009 as part of the Marianas Trench Marine National Monument. Covering more than 95,000 square miles, it is one of the world’s largest marine protected areas.

It’s very dark, so the animals must use many other senses other than sight to understand their surroundings, find food and escape from enemies. The water is also very cold — slightly above freezing — and its pressure is extremely high. That means only certain animals can live there, like shrimp, crabs, and starfish.

So far, the expedition’s cameras have filmed a variety of rarely seen deep-sea creatures, including ghost sharks, huge lobsters, and sea pigs. Perhaps the most amazing sight is beautiful red jellyfish that scientists have never seen before.

Scientists hope this expedition will help them unlock the mysteries of the Mariana Trench. They’ll learn about the deep-sea animals and plants found there. They’ll also study its unique features, including underwater mountains, mud volcanoes, and hot springs produced by the volcanoes.

They say that this knowledge will also help scientists better understand how the deepest part of the ocean affects the rest of the world. "The ocean plays a role in the air we breathe, the food we eat, and the transportation of the goods we buy — not to mention the weather and climate change," a scientist said. "The deep sea may also hold cures for diseases. How will we know what is out there if we aren’t looking into it?"

1.What do we know about the Mariana Trench from the text?

A.Sea life can hardly be found there.

B.It has never been explored by humans.

C.It’s the world’s largest marine protected area.

D.It’s lively even as the deepest place in the world.

2.What does the author want to say in Paragraph 4?

A.Living conditions are tough there.

B.The surroundings make animals much stronger.

C.Animals there are slow in reacting to potential threats.

D.Animals’ sight is severely damaged by high water pressure.

3.What is implied in the scientist’s words in the last paragraph?

A.He feels proud of what they have done for humans.

B.It’s worthwhile to take effort to explore the Mariana Trench.

C.Scientists should spend more time studying the oceanic climate.

D.There’re many challenges for the scientists to explore the ocean.

4.What is the best title for this text?

A.The Most Mysterious Ocean

B.A Special Experiment on the Ocean

C.Searching for Precious Animals

D.Exploring the Deep Sea