题目内容：

    It is becoming increasingly important for researchers to closely monitor our ocean life. However, observing sea creatures up close is almost impossible since human presence scares them. Now, thanks to the The Soft Robotic Fish, also known as SoFi, researchers may be able to keep a close eye on the sea creatures.

Built by MIT Computer Science and Artificial Intelligence Laboratory (CSAIL), the white remote-controlled robot resembles the real fish, complete with a tail that waves from side to side. Though not the first autonomous underwater vehicle (AUV) created to monitor the ocean, SoFi settles many of the problems that have blocked the usefulness of previous robot fish.

Previous AUVs have had to be linked to boats because of radio frequency communications don’t work well underwater. To overcome the problem, Director of the CSAIL Daniela Rus and her team used sound waves. The technology can travel greater distances allowing divers to pilot SoFi from up to 50 feet away.

Also limiting the usefulness of traditional AUVs is the risk of collision. With the outside made of soft silicone (硅树脂) rubber and flexible plastic that keeps its inbuilt electronics dry, SoFi poses no such danger. “Collision avoidance often leads to unnecessary movement, since the robot has to settle for a collision-free path,” says Rus. “ In contrast, a soft robot is not only more likely to survive a collision but also could use it as information to form a more workable movement plan next time around.”

During test dives, SoFi moved alongside the ocean life at depths of 50 feet for up to 40 minutes at a time, taking photos and making videos. The researchers say sometimes the fish would swim alongside the strange-looking robot-fish out of curiosity, while at other times they took no notice of its existence.

While SoFi presently only records video, future versions will include sensors. The researchers also hope to make it more autonomous. “We imagine someday it might help us uncovers more secrets from the amazing underwater world that we know so little about,” says Rus.

1.What can we learn about SoFi?

A. Its tail is flexible.    B. It is the first AUV.

C. It is closely controlled.    D. Its presence scares sea animals.

2.What can be learned from paragraph 3?

A. Sound waves travel faster than radio.

B. Radio does not work well underwater.

C. Previous AUVs use radio to communicate.

D. A boat travels along with SoFi on the water.

3.How does SoFi differ from traditional AUVs?

A. It is controlled above.

B. It can avoid a collision.

C. It can smartly adjust its movement plan.

D. It is set for a collision-free path.

4.Where is the passage possibly taken from?

A. A news report.    B. A science fiction.

C. A social website.    D. A short biography.