【推荐1】As California gray whales wind their way south along North America's Pacific coast, researchers are watching, worried about another year of unexplained die﹣offs.

Last spring and summer, 215 whales inexplicably (说不清地) washed up along North America's West Coast. Concerned, the U.S. National Oceanic and Atmospheric Administration called for an investigation, bringing together researchers from the Arctic to Mexico to explore the strandings (搁浅) in a uniform manner.

According to the scientists involved with the investigation, it's still unclear what caused the 2019 die﹣off and whether the whales will fare better this year.

California gray whales migrate 5, 000 miles every year from the Arctic to Mexico's Baja. Their journey is the longest migration, and full of dangers such as ships and plastic rubbish. The journey back north is particularly dangerous because gray whales only eat while in the Arctic; therefore, they are running on empty as they make their return trip from Baja.

Data and observations collected this past summer by researchers based at NOAA's Alaska Fisheries Science Center have raised more questions than answers. For instance, 15 gray whales were spotted in one day in the eastern Beaufort Sea-a rare sighting for a species usually seen getting fat at their feeding grounds. But with the sea ice forming later in winter and breaking up earlier in summer, scientists wonder whether gray whales will continue to move farther east to new feeding areas.

In addition to changes in food availability, as sea ice decreases, whales are running into more and more ship traffic in these remote waters. Ship strikes and being trapped in fishing gear are common causes of whale injury and death.

Maggie Mooney﹣Seus, spokeswoman for the Alaska Fisheries Science Center, said, "We are working to determine future whale research plans that may help shed light on this and other relevant questions."

【推荐2】A beloved pet that went missing in the Highlands area of Vancouver Island was found seven days later by an army of volunteers and was reunited with her owner.

The mastiff-retriever cross (马士提夫獒犬), named Luna, was found trapped on a narrow cliff ledge (岩架), and was reunited with her owner after a heroic rescue last month. It’s believed that Luna had chased an animal out of her yard and got lost, somehow falling off a cliff and landing on a two-foot-wide ledge. She remained there, alone, as her owner and searchers wildly looked for her.

“It was terrible because it was getting colder and she always sleeps next to me or my daughter,” said Saryta Schaefer, Luna’s owner.

After she’d been missing for several days, there was a break in the case. Across the water, Ron Cheeke had heard Luna’s cries for help. Cheeke decided to record the sound and notify the pet rescue group ROAM. He even went so far as to search the area in a boat to try to locate the exact source of the sound. “I used a pot, and every time I banged on the pot, the dog barked back,” Cheeke told CTV News.

Eventually, after searching on both water and land, a team found the scared dog and used a harness (保护带) to pull her back to safety and to her owner. “I almost fell over when I saw her-it was quite exciting,” said Schaerer.

Cheeke said his own dog had died recently and he was motivated to help. “I lost my dog last year, so it was good,” said Cheeke. “It’s good to see it back with its owners."

“There’s no feeling like it. When you’re involved with this and you get the owner back with the pet, it’s worth all the money in the world,” added ROAM volunteer Andy Carswell.

【推荐1】Teenagers need eight to ten hours of sleep per night. However, in adolescence (青春期) changes to the body’s sleep cycle make it difficult for teens to fall asleep early. Many cannot fall asleep until 10:30 p.m. or even later and most of them will feel sleepy if they have to get up too early.

Scientists recommend that both middle and high schools begin no earlier than 8:30 a.m. Later school start times support the natural needs of teenagers and increase their sleeping time.

Here are some other benefits of later school start times:

More time for a healthy breakfast

When running late in the mornings, students are likely to go without breakfast. With an empty stomach, one finds it difficult to focus (集中) in class. When they are always in a hurry, students may form unhealthy eating habits.

With extra time before going to school, students can eat a well-balanced breakfast and focus more on learning.

Fewer behavioral (行为的) problems

Teens experience mood changes as a common result of this special period of life. Less sleep may cause worries, stress and unhappiness.

When they get enough sleep, students are calm and peaceful and their moods do not change suddenly. They’re less likely to feel worried, unhappy or get angry. For parents, children with more sleep are easier to live with.

Better performance (表现) in study

Sleep loss hurts attention, memory and brain development. Students with less sleep have difficulty paying attention in class and are likely to have lower grades. Students with enough sleep can be more energetic during the day and more willing to learn. They are also less likely to fall asleep in class and more able to understand what they learn.

In conclusion, starting school later helps students get a better night’s sleep. It improves their chances of eating, behaving and performing better.