3 . The sound coming from Taronga Zoo Sydney in Australia may sound like the cries of a human baby.     1     It’s just a brown, long-tailed bird named Echo that has learned how to mimic (模仿) the cries of human babies.

Echo is a superb lyrebird (琴鸟), an Australian bird named for the shape of its tail.    2     It’s a U-shaped stringed instrument that was popular in ancient Greece. The zoo says lyrebirds are experts at mimicking. They can mimic any sound in their immediate surroundings, including those from car engines, as well as animal sounds, such as dog barks and bird calls.

Seven-year-old Echo can mimic the sound of a fire alarm and the “leave immediately” announcement at the zoo, Leanne Golebiowski, a bird expert at Taronga Zoo Sydney said     3     But it’s not clear how Echo perfected the calls, as the zoo is closed to visitors because of COVID-19 lockdowns. Glebiowski said, “I can only guess that Echo picked it up from our guests.     4     But this concerns me, as I thought the zoo was a happy place for families to visit!”

Male lyrebirds use their mimicking talents mainly for mating. During their breeding sea-son, male lyrebirds can be heard singing for up to 4 hours a day. Their songs consist of a lot of different bird calls that they have picked up from their surroundings.     5    

A．However, don’t be alarmed.

B．The female should stay with him.

C．The number of lyrebirds is on the increase.

D．The tail looks like an instrument known as a lyre.

E．Obviously, he has been working on his craft during lockdown.

F．About a year ago, Echo started practicing baby cries, she said.

G．But sometimes their mating songs include other non-bird sounds.

4 . Most polar bears could disappear by the end of the century, scientists say. Global warming is to blame. According to a study published this month in Nature Climate Change, most polar bear populations will be in serious decline by 2080. The cause is melting sea ice.       

Polar bears hunt seals on the ice. Without ice, the bears must wander on the shore, where they are spending more and more time away from their main food source. That means the animals could starve.

“There’s not enough food on land to sustain a polar bear population,” Péter K. Molnár told the New York Times. He is the study’s lead author.

Lack of food leads to another problem: Mother bears may not be fat enough to produce milk for their cubs. Some bear populations could stop having babies, leading to a rapid decline in numbers.

Arctic sea ice usually melts in the spring and summer, then grows in the winter. But now, the ice is taking longer to grow back. Weather statistics say the Arctic is warming twice as fast as the rest of the planet. Ice in the region has declined 13% every 10 years since the 1970s.

The Arctic is home to roughly 25,000 polar bears. Scientists have long known that the animals are in danger. This study, which looked at 13 of the world’s 19 polar bear populations, is the first to identify when they could disappear.

But the study also notes that it is still possible to slow Arctic melting. The world can reduce the burning of fossil fuels and lower the greenhouse gas emissions that contribute to climate change. It would have to be a drastic reduction. Bringing emissions to only a moderate level will still mean the loss of some polar bears.

Saving the bears is up to us, Holland says. “I believe that there is hope,” she says. “But humans need to act quickly to turn that hope into a reality.”

1. Why are polar bears in danger of disappearing?

A．Lack of seals.	B．Global warming.
C．Less milk for cubs.	D．The loss of home.

2. What does the underlined word “ sustain” in paragraph 3 probably mean?

A．Reduce.

B．Suffer.

C．Support.

D．Increase.

3. What is Holland’s attitude toward saving the polar bears?

A．Doubtful.

B．Neutral.

C．Negative.

D．Positive.

5 . Due to climate changes, Arctic ice is breaking up earlier in the spring, and its area is decreasing. This is creating problems for polar bears that make their homes off northern Alaska and in Hudson Bay.

Polar bears off Alaska normally hunt and raise their young on ice sheets that float on the ocean. But as the ice has melted, the polar bears have been forced to spend more time on land. There, they have begun to frequent beaches, feeding on the remains of whales caught by native hunters. For polar bears, this food is less nutritious than seals that they normally catch on ice sheets. The shrinking (减少) ice has also forced more polar bears into the ocean. In the past, they only had to swim short distances between ice sheets. But as the ice has shrunk, polar bears have been forced to swim longer and longer distances in the open ocean. This poses a severe danger during rough weather, and an increasing number of drowned polar bears have been observed.

In Hudson Bay, the ice breaks up three weeks earlier in the spring now than it did 20 years ago. Polar bears on Hudson Bay fast (绝食) during the summer, waiting for ice to form in the fall to hunt. Every year, the summer gets longer, and the bears get skinnier. Over the past 25 years, the average weight of the female bears has dropped 68 kg. This loss affects their ability to reproduce, and already the number of births has dropped by 15 percent. Unless the bears can learn to survive these climate changes, these giants of the ice may one day disappear.

1. What is Arctic ice doing earlier each year?

A．It's freezing.	B．It's hardening.
C．It's melting.	D．It's expanding.

2. What is true of polar bears that are spending more time on land in Alaska?

A．Their young are dying.	B．Their diet is changing.
C．Their health is improving.	D．Their families are growing.

3. What does the writer imply about female polar bears in Hudson Bay?

A．They are having fewer young now.	B．They suffer from various sicknesses.
C．They don't need stronger protection.	D．They can't find enough good males.

4. In which publication would you most likely find this passage?

A．Medical News.	B．Society Today.
C．Wildlife Journal	D．Design Magazine.