There’s no doubt that dogs are insightful and sensitive beings，with the ability to sense emotions and read humans’ facial expressions. The American Kennel Club (AKC) says dogs combine hearing and sight     1     (correspond) happy and angry faces with happy and angry sounds. Researchers have found that dogs can distinguish the positive sound of laughing     2     the negative sound of crying. The dogs were found to be more upset and stimulated by the negative sounds than positive ones.     3     2018 study published in Scientific Report, a peer-reviewed online journal published by Nature Research,     4     (show) that dogs use the right side of their brain for processing negative emotions and the left side for positive ones.

Speaking to Newsweek, AKC's officer. Dr. Jerry Klein, explained dogs can certainly become     5     (depress) and anxious. There have been reports of dogs     6     (experience) depression and loneliness following the     7     (lose) of an owner or a “fellow member” of their pack, as well as a change from     8     (they) normal routine.   “But whether dogs get ‘sad’ is less certain,” Klein told Newsweek. Klein said from a     9     (strict) scientific standpoint, there isn’t strong evidence that dogs feel     10     people would classify as sadness. “Dogs live more in the moment and don’t have the ‘sclf-consciousness’ to inwardly think like people do.”

Scientists: Hungry Polar Bears Eating Food Waste to Survive

Scientists from the U.S. and Canada say Arctic warming is reducing the food supply for polar bears. The animals are forced     1    (search) for food at waste sites. That is causing problems for     2    the bears and humans.

With the usual food running low, the bears are coming off the ice and onto land. They get    3    (close) to areas where humans place waste, including bones from whale hunts and used food packages.

The bears often end up     4    (eat) the food packaging when trying to get to the food inside. Since their bodies cannot break down the material, the bears can develop blockages that can result     5     sickness and even death. In     6    (add), people living close to the area     7    (occasional) shoot the bears because they fear the animals might hurt people.

Up to now the bears     8    (find) at garbage collection places in Russia and in the American state of Alaska. The problem will only get worse for the bears as more humans move into their territory. One area where the bears live is Nunavut, Canada. The human population there    9    (expect) to increase by over 50 percent by 2043.

As more humans move in, the waste becomes more of a problem because it is hard to manage in frozen lands. The ground is frozen,    10    means the garbage cannot be buried. It is costly to send the waste out on trucks.

The Burmese snub-nosed monkey (仰鼻猴) is a     1     (critical)threatened species of colobine monkey. The young animals’ coloring differs markedly from that of the adults. The species first gained the attention of scientists     2     (research) the hoolock gibbon (白眉长臂猿) in Burma in early 2010. It wasn’t until 2012 that a camera was set up     3     (capture) the first images of the new species. The     4     (know) population of the snub-nosed monkey in Burma is about 260-330 individuals. They are currently threatened by the destruction of their forest habitats from logging (伐木作业) and development in the area.

In the last 500 million years, there have been five times when life on Earth has almost ended. A 2015 study by scientists     1     were based on Brown University and Duke University in the US, look at     2     quickly species die out due to natural causes. They found that human activity is causing species to die out 1,000 times     3     (fast) than normal.