【推荐3】Fewer than 400 North Atlantic right whales remain in the wild, and not even 100 of them are breeding females. Their biggest survival threats are boat strikes and getting caught in fishing gear. Protecting these whales, such as by turning boats from dangerous encounters, requires positioning them more reliably -- and new technology, described in the Journal of the Acoustical Society of America, could help make that possible.

To listen for marine life, researchers often install underwater microphones called hydrophones on buoys (浮标) and robotic gliders (滑翔机). The recorded audio is changed into spectrograms -- visual representations of sound used to precisely recognize, for instance, specific whale species’ calls. But those distinctive sounds are often drowned out by other noise. In recent years researchers have used a machine-learning technique called deep learning to automate this analysis, but background sounds still block reliability.

Now researchers have trained two deep-learning models specifically to cut through the noise. They started by giving the models thousands of “clean” spectrograms with only North Atlantic right whale calls. Then they slowly added in thousands of spectrograms mixed with typical background sounds, such as tanker engines. The program can successfully turn noisy spectrograms into clean ones, reducing false alarms and helping spot whales before they reach dangerous areas, the scientists say.

Shyam Madhusudhana, a Cornell University data engineer, who was not involved in the study, says he would want to see if such models could be used to locate other marine mammals (哺乳动物), too. “Humpback whales and dolphins have much more complex speech pathways than the right whale,” he notes. And University of East Anglia machine-learning researcher Ben Milner, one of the study’s authors, wants to take this technology above water as well -- to Ukrainian forests, where he hopes to identify animals near the site of the 1986 Chernobyl disaster.

University of St. Andrews behavioral ecologist Peter Tyack, who was not involved in the study, says this new system should be used to figure out where whales are throughout the year, so that these areas can be protected. “In terms of estimating the density and the number of these whales in places where it’s hard to see them,” Peter says, “this technology could be fantastic.”

But he warns that it should not be the only approach to preventing ship strikes. In his work, Tyack has found that North Atlantic right whales can be silent for hours at a time -- so passive sound monitoring could easily miss one. And killing just a few, he adds, “could lead to extinction of the population.”

1. What does the new technology do to help protect the North Atlantic right whales?

A．Locating the right whales precisely.

B．Turning boats to encounter the right whales.

C．Guiding the right whales away from fishing boats.

D．Positioning fishing boats reliably and thus deadly strikes.

2. What is a major contribution of deep-learning models to reducing background noises?

A．They turn off the nearby alarms that may create background noises.

B．They can eliminate disturbances shown on a spectrogram sheet.

C．They add thousands of mixed sounds such as vehicle engines.

D．They can prevent whales from reaching dangerous areas.

3. It can be learned from the passage that________.

A．Shyam and Ben are both scientists at different universities who know each other well

B．all of the three scientists consider the extended use of the technology could face challenges

C．Shyam and Ben both hope that the deep learning model can go beyond its current application

D．Peter thinks the technology should have been used to figure out where it’s hard to see the whales

4. Which one of the following might be the best title of the passage?

A．Latest Techs on Marine Lifesaving

B．Save the Right Whale by Noise-cutting

C．See Whales’ Noise through Human’s Eyes

D．Non-professional Scientists’ Role in Saving Whales

【推荐2】Blood donations save lives. But blood can only be stored under refrigeration (冷藏) for up to six weeks. After that, it’s no longer usable for transfusions(输血).

“Because of that limitation, people have to continually donate blood to meet the needs. But also, in places where refrigeration may not be available, that can also be a challenge. It’s difficult to have blood available when needed.” University of Louisville bioengineer Jonathan Kopechek says. He also says disruptions to regular blood donations due to COVID-19 have put stress on the blood supply, and   COVID-19 strengthens the need for more reliable long-term storage methods.

But it’s pretty rare because of all the challenges and complexities with that process. Instead Kopechek’s team has developed a method of preserving blood so it can be stored in a dehydrated(脱水的) state at room temperature. To do so, they turned to an unusual preservative(防腐剂): a sugar called trehalose, which is a common ingredient(成分) in donuts（甜甜圈）to help make them look fresh even when they might be months old, and people wouldn’t know the difference.

At that point, the blood could be dried and made into a powder(粉末). And then we can rehydrate(再水化) the blood and have it return back to normal. The team is still trying to improve yields but thinks the dried blood could be stored at room temperature for years. Kopechek says the technique could be ready for clinical trials in three to five years. If successful, it could be used to create stores of dried blood in case of future pandemics or natural disasters, and for first aid work, military operations or even missions to Mars. Maybe first aid kits on the Red Planet will include dried red blood cells.

1. Why we need a more reliable method to preserve blood?

A．Refrigeration can’t be afforded.

B．The cost to store blood is very high.

C．People can’t donate their blood for COVID-19.

D．Blood can only be stored under refrigeration for a short time.

2. What makes the food or blood look fresh?

A．Trehalose.	B．Donuts.
C．Powder.	D．The new technique.

3. What can we know about the technique?

A．It is successful now.	B．It has been put into use.
C．It will be widely used.	D．It has been researched for 3 to 4 years.

4. What is the text mainly about?

A．How to store blood.

B．Shortage of refrigeration .

C．A new technique of storing blood.

D．A new technique used in many fields.

【推荐3】If sticking with an exercise habit is a challenge for you, there may be an app for that. In a University of Pennsylvania trial, smartphone games helped subjects become more active.

Participants were randomly assigned to one of three versions of a game that recorded how many steps they took each week. The first version placed them in direct competition with others. In the second version, they worked as a group to gain points. In the third, players earned points on their own but were asked to choose a friend or family member to be their supporter. This person received an e-mail each week reporting on the player's performance in order to help cheer her or him on.

On average, all three groups took more steps than usual. That said, certain versions of the game worked better for people with different personality traits. For instance, players who were more outgoing and more motivated to persevere with their goals tended to accumulate more steps in the competitive mode. In contrast, quiet players responded well to the game whether it was competitive, cooperative, or supportive. A third type, made up of those who were prone to take risks with their health and safety (by not wearing a seat belt, for example), was not helped by the game at all.

So though not all of us benefit, exercise gamification can work—and work especially well when you keep your personality in mind as you choose from among the many available apps.

1. What can we learn from paragraph 2?

A．Each participant chose their version of a game.

B．The second version got the participants to cooperate to earn points.

C．Friends helped the player in the third version earn more points.

D．The first version placed participants in indirect competition.

2. In which mode did outgoing players exercise more?

A．Cooperative mode.	B．Competitive mode.
C．Supportive mode.	D．No mode.

3. Which of the following can best replace “were prone to” in Paragraph 3?

A．were likely to	B．were unwilling to
C．were afraid to	D．were hesitant to

4. What is the best title for the text?

A．Challenge your body with different game versions.

B．Change your personality to suit different game versions.

C．Choose an exercise app with your personality in mind.

D．Cooperate with your family to accumulate more steps.