3 . Most people feel that dreams are unique to humans, but many dog owners will likely disagree. They have noticed that their dogs at various times during the sleep may shake legs, snort (哼) and sometimes growl (低声吼叫) which gives the impression that they are dreaming. These things may wonder us about whether dogs dream.

Scientists confirm that dogs probably do dream. It turns out that dog brains and human brains have many similarities during sleep cycles. Researchers used special machines to measure electrical activity in a dog’s brain and a human’s brain. Scientists already knew that when humans dream, a certain part of the brain is active during sleep. Researchers discovered that the same part of the brain is active in sleeping dogs. Scientists have other data that back up these findings.

Many people dream that they are trying to move but cannot. Interestingly, part of that experience is not a dream. When people sleep, the brain produces a chemical that causes the dreamer to become temporarily paralyzed (使麻痹). Researchers think this happens so that people cannot physically act out dreams while they are sleeping. Dog brains make the same chemical. In one study during which this chemical was blocked, sleeping test dogs performed physical activities, such as standing up, sniffing around the room for imaginary rabbits, or chasing imaginary balls.

Because of these similarities, researchers believe that the content of a dog’s dream might come from the same source as a human’s dream. “People’s dreams are usually based on things they did that day,” says Dr. Samantha Hudspith. “So we have reasons to believe that dogs dream about the things they’ve done that day. Of course, there will never be a way to prove this. Dogs cannot describe their dreams the way that humans can.”

4 . All Ric O Barry wants is to stop the dolphin-killing, so he is headed to this seaside Japanese town, Taiji. The American activist, who is the star of a new award-winning documentary that portrays the dolphin-killing here, got an unwelcome reception when he showed up here this week for the start of the annual hunt.

His movie, The Cove (海豚湾 ), directed by National Geographic photographer Louie Psihoyos, was released in the United States a month ago but has not yet to come out in Japan.

Scenes in the film, some of which were shot secretly, show fishermen banging on metal poles stuck in the water to create a wall of sound that scares the dolphins — which have supersensitive sonar (声呐系统) — and sends them fleeing into a cove.

There, the fishermen sometimes pick a few to be sold for aquarium shows, for as much as $150, 000. They kill the others, spearing the animals repeatedly until the water turns red. The meat from one dolphin is worth about 50, 000 yen, and is sold at supermarkets across Japan.

Greenpeace and other groups have tried to stop the hunt for years. Activists hope The Cove will bring the issue to more people internationally—and eventually in Japan.

Already, the Australian town of Broome dropped its 28-year sister-city relationship with Taiji last month, partly because of the movie.

“Some regions have a tradition of eating dolphin meat,” said fisheries official Toshinori Uoya. “Dolphin-killing may be negative for our international image, but it is not something orders can stop.”

The town government in Taiji — which has made whales and dolphins its trademark — refused to comment about The Cove, or the growing international criticism against dolphin-killing.

Many in Taiji take the dolphin hunt for granted as part of everyday life. They are defensive about The Cove, seeing themselves as powerless victims of overseas pressure to end a simple and honest way of making a living.

5 . Nola (August 21, 1974—November 22, 2015) was a northern white rhino who lived at the San Diego Zoo Safari Park near Escondido, California. At her death, she was one of only four remaining northern white rhinos in the world. The other three lived in Kenya. World Rhino Day,   held on September 2,   is to raise awareness(意识) of the less than 30, 000 other rhinos left on Earth.

''Rhinos need our help today, not tomorrow,'' Nola's lead keeper Jane Kennedy said. ''Last year we lost over 1, 200 rhinos just in South Africa. If we continue to lose more than 1, 000 rhinos a year, in 10 to 20 years all the rhinos on the planet will be gone. ''

''Unfortunately, most animals are in danger of dying out because of humans,'' Kennedy says. ''Humans have either poached animals, or because there are over seven billion of us, we've taken up too much of the world's resources''. Poachers illegally hunt rhinos for their horns. They sell the horns for thousands of dollars per pound, to be used for art, jewelry, and decorations. Experts believe that one rhino is poached every eight hours.

In 1975,   the San Diego Zoo Institute for Conservation Research started the Frozen Zoo,   a program through which researchers have collected cell (细胞) samples from more than 8, 000 different types of animals,   including the northern white rhino. Scientists hope that by studying the rhino cells, they will get greater understanding of it, and will find ways to increase its numbers.

Jane Kennedy describes World Rhino Day as a celebration of rhinos along with an awareness campaign for everybody across the world to know that rhinos need our help. ''At the San Diego Zoo, children and adults are welcome to visit and speak with zookeepers to learn about rhinos. But you don't have to live in San Diego to celebrate World Rhino Day. It is observed around the world, with zoos and wildlife parks holding special events and programs to teach people about rhinos, and enable them to see the animals up close. For more information, go to www. worldrhinoday. org.

6 . It is a question that has long puzzled scientists—exactly why are tigers orange? One might think it makes them more obvious-particularly against a leafy green forest background. William Blake summed it up in his famous poem known by generations of schoolchildren: “Tyger, tyger, burning bright / In the forest of the night.” But now the answer is at hand.

While obvious to us, computer simulations (模拟) of what the big cats look to the main animals they hunt for, deer, show a different picture. Humans with normal colour vision, can see red, blue and green colours. But deer can only pick up blue and green light, they are effectively colourblind to the colour red, like some humans. It means the tigers’ orange colouration looks green to them, allowing them to mix perfectly into the background, new research claims.

Dr John Fennell at the University of Bristol and colleagues said that they used computers to estimate how noticeable a given animal was. They did this by using images of the environment in which the animal lives, and then creating images to see whether the camouflage helps the animal to mix in.

Dr Fennell writes that by simulating what the world looks like to animals who are “two-colour vision”—someone who cannot discover the difference between red and green—“we also identify the most suitable colours for hiding and visibility”.

Dr Fennell writes in the Royal Society Journal Inter face: “Considering the coat of a tiger, it has fur that appears orange to a three-colour vision observer rather than some shade of green, though the latter should be more appropriate color for an attack hunter in forests. However, when viewed as a two-colour vision observer, the tiger’s colour is very effective.”

The question then arises as to why tigers don’t grow green coats. Dr Fennell and colleagues write that mammals (哺乳动物) are not able to produce green fur. To do so would “require a significant change to mammalian biochemistry”. There is only one mammal known to have green fur but this is achieved through what might be considered as, well, cheating, not exactly real.

7 . Color is in everything we touch, taste, smell and feel. It evokes(唤起) emotion without any thought.    1    We are all familiar with it, but do you know the following facts?

Silver will save your life. When buying a new car and finding yourself facing various choices, you can’t think clearly. Your best choice is to go with silver. Silver­colored cars are least likely to be involved in a car accident.     2     Another reason is the silver color's ability to have a look of cleanliness.

    3     Tough prisoners and crazy patients？It is the color commonly used to help calm down those who are out of control. So it surely has a useful place and a purpose, other than decorating a dress or Barbie's dream house.

Yellow makes you hungry. Yellow and orange are not recommended for use in kitchens, as they have a positive influence on your appetite.    4     I’m not normally one for conspiracy(阴谋) theories­ but perhaps there’s something in it for them if we remain ignorant of yellow’s effects.

Color is an imaginary friend. Technically, it’s all in our heads: color does not exist at all.     5     So, if you start a heated debate over color combinations with someone that you are certain has a low IQ or is just color­blind，remember it's a pointless argument and you should drop it instantly. You're both wrong.