1 . When I first arrived in Santiago, Chile, and took a walk around the city center, one of the first things I noticed was how many street dogs there were.

On every corner there was a sleeping _______. At every traffic light there was a dog _______ to cross. By every shop there was a dog waiting for _______. At first I was _______ as I thought they might be _______ or unfriendly. However, I have been here for more than a year now and every street dog I have seen has been quiet and _______.

The dogs are _______ and welcomed here in Chile. They are _______ given food and water by the public. Some people even _______ jackets for the dogs or put out beds for them to sleep in.

There are an estimated 2.5 million street dogs in Chile and the canine (犬的) population is ________. Some people believe that the ________ is getting out of control and that it is ________ to have so many dogs on the streets. The dogs can sometimes cause ________ such as car accidents if they run into the road. Many Chileans think that all the street dogs should be sterilized (使绝育) so that they cannot ________. Others think that the street dog population should be culled (i.e. reducing the population by killing them).

The future of street dogs is ________, but for now it looks like they are here to stay, with their population expanding year by year.

2 . 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.”

3 . It’s important to learn about protecting our environment. Here is a 5R rule for us:

1. Reduce

If you want to reduce waste, you should use things wisely. A large number of trees are being cut down to make paper. If everyone uses a little paper carelessly and throws it out, soon we would not have any trees left. Other things are also being wasted, and people don’t know what to do with the waste in big cities. So it is necessary to reduce the waste.

2. Reuse

You should always think of reusing the usable things before throwing them out. Give your clothes you do not use or the ones which are too small to the poor. In a family, you may pass on such clothes to younger brothers or sisters.

3. Recycle

Bottles, cans and paper can easily be recycled. By doing so, we save lots of time and money. For example, coke cans are sent to a factory, where they are smashed flat and melted and the metal things are made for new coke cans.

4. Recover

When you buy a box of apples, there may be a few rotten apples, you have two choices: one is to throw the whole apples away, or you could cut off the rotten parts and use the good parts. In this way, you are recovering the eatable parts of food.

5. Repair

If one of the legs of your table is broken, you can repair it. If you want to change for better ones, it is better for you to sell the old things or give them to other people who can use them after doing some repair. It is true that North America is a “throw-away” society, but the time has come to change our way of life so that we can protect our environment. Every one of us should try our best.

4 . Listening to birds and water can lower stress and improve mood, study finds. Researchers have long known there are benefits from being in nature. Living around trees can help you live longer. Walking in the woods is good for your mood. Being near water can have positive effects on your well-being.

A new study finds that natural sounds offer health benefits too. There is plenty of evidence that spending time in natural areas is good for our health-but typically this research is done from a visual perspective, but we are curious what the role is of sounds we hear in these spaces.

Some examples they found reported in those studies included decreased pain, lowered stress, improved mood, and better cognitive(认知的) function. With these results in hand, they then listened to audio recordings from 251 sites in 68 national parks across the United States.

The sites with the most natural sounds and the lowest man-made sounds were located in Alaska, Hawaii, and the Pacific Northwest and were far from urban areas. Only three locations with high natural sounds and low noise pollution were within 100 kilometers(62 miles)of urban areas.

However, despite human-made noises being heard most of the time at sites in urban locations, birds were still heard about 60% of the time and geophysical sounds like wind and rain heard about 19% of the time.

Not all natural sounds deliver the same benefits, the researchers found. For example, they discovered that the sounds of water had the largest impact on improving positive emotions and health outcomes, while bird sounds ease stress and annoyance. And the sounds of both birds and water were heard more than 23% of the time in the national park recording sites.

Interestingly, there was also some evidence that natural sounds have benefits over silence. There was also evidence that more different types of natural sounds-more types of birds singing rather than just one type of bird-have benefits over fewer sounds.

5 . Luke is a cute dog, living together with me for five years. We get lots of   _________   in our area during the summer season. Many forests are badly _________ by fire each year. That hot summer, not far from our shelter, a forest   _________ fire. It was July, and there had been a heat wave going on for three days.

Somehow, Luke rushed toward the forest. There was no longer any hope at that moment to wait for Luke to come back to the _______. In fact, I was waiting for firefighters to tell me that he had _______ in the forest. Suddenly, a fireman burst into my office and     _______     me that Luke had succeeded in saving four kittens who had been _______by the flames. I _______   accompanied the fireman to the forest to get him back. _______ we got to the scene of the incident, we didn’t see Luke. Then we heard the   ________ of a dog barking in the forest. I ________the barks as Luke’s. The firemen ________ the tracks of the dog until they found him barking loudly by the side of an injured ________. Thanks to Luke, four kittens and a fireman were saved. This true story shows us that pets are loving, caring and compassionate. We should love and ________them. Little animals can do     ________     things for humans.

The world itself is becoming much smaller by using modern traffic and modern communication means. Life today is much easier than it     1    hundreds of years ago,       2     it has brought new problems. One of the    3     (big) is pollution. Pollution comes in many     4     (form). We see it, smell it, drink it and even hear it.

Man has been polluting the earth. The more people, the more pollution. Many years ago, the problem was not so serious    5     there were not so many people. When the land     6     (use) up or the river was dirty in one place, man moved to another place. But this is no longer true. Man is now     7    (slow) polluting the whole world.

Air pollution is still the most serious. It’s bad for all living things in the world. Water pollution kills our fish and pollutes our drinking water. Noise pollution       8       (make) us angry more easily.

Many countries are making rules     9       (fight) pollution. They stop people from     10     (burn) coal in houses and the factories in the city, and from putting dirty smoke into the air.