I'm not sure     1     is more frightened, me or the female gorilla(大猩猩）that suddenly appears out of nowhere. I'm walking on a path in the forest in the Central African Republic. Unexpectedly, I'm face-to-face with the gorilla, who begins screaming at     2     top of her lungs. That makes her baby scream, and then a 400-pound male appears. He screams the

    3    (loud)of all. The noise shakes the trees as the male beats his chest and charges toward me. I quickly lower myself, ducking my head to avoid     4    (look) directly into his eyes so he doesn't feel    5    (challenge).

My name is Mireya Mayor. I'm a     6    (science)who studies animals such as apes and monkeys. I was searching     7     these three western lowland gorillas I'd been observing. No one had seen them for hours, and my colleagues and I were worried.

When the gorillas and I frightened each other, I was just glad to find     8    (they) alive. True to a gorilla's unaggressive nature, the huge animal     9    (mean)me no real harm. He was just saying: "I'm king of this forest, and here is your reminder!" Once his message was delivered, he allowed me     10     (stay)and watch.

3 . Let's take a minute to think about the water we use. The human body is 60% water and we need to drink lots of water to be healthy. When we are thirsty we just go to the kitchen and fill a glass with clean water.

    1    For example, farmers, who produce the food we eat, use water to make the plants grow. When we turn on a light or switch on a TV or a computer we use energy and we need water to produce this energy.

The truth is that we are lucky enough to have clean water whenever we want，but this is not the case for many people around the world.    2    That's around one in 10 people in the world. If we drink dirty water，we can catch diseases from the bacteria and become ill. Every year over 500，000 children die from diarrhea(腹泻)from dirty water. That's around 1，400 children every day！Also，in some countries children walk many kilometres every day to get water.    3    Therefore，they don't have time to learn how to read or write and don't get an education.

    4    On this day every year，countries around the world hold events to educate people about the problems of dirty water and that clean water is something that everyone should have around the world. At one school in the UK，children between the ages of 10 and 15 walk 6km with six litres of water.    5    People give them money to do this and all the money helps get clean water to as many people as possible around the world.

4 . California has lost half its big trees since the 1930s, according to a study to be published Tuesday and climate change seems to be a major factor(因素).

The number of trees larger than two feet across has declined by 50 percent on more than 46, 000 square miles of California forests, the new study finds. No area was spared or unaffected, from the foggy northern coast to the Sierra Nevada Mountains to the San Gabriels above Los Angeles. In the Sierra high country, the number of big trees has fallen by more than 55 percent; in parts of southern California the decline was nearly 75 percent.

Many factors contributed to the decline, said Patrick McIntyre, an ecologist who was the lead author of the study. Woodcutters targeted big trees. Housing development pushed into the woods. Aggressive wildfire control has left California forests crowded with small trees that compete with big trees for resources(资源).

But in comparing a study of California forests done in the 1920s and 1930s with another one between 2001 and 2010, McIntyre and his colleagues documented a widespread death of big trees that was evident even in wildlands protected from woodcutting or development.

The loss of big trees was greatest in areas where trees had suffered the greatest water shortage. The researchers figured out water stress with a computer model that calculated how much water trees were getting in comparison with how much they needed, taking into account such things as rainfall, air temperature, dampness of soil, and the timing of snowmelt(融雪).

Since the 1930s, McIntyre said, the biggest factors driving up water stress in the state have been rising temperatures, which cause trees to lose more water to the air, and earlier snowmelt, which reduces the water supply available to trees during the dry season.

7 . Many cities around the world today are heavily polluted. Careless methods of production and ________ of consumer demands for environment friendly products have ________ the pollution problem. One ________ is that millions of tons of glass, paper, plastic, and metal containers are produced, and these are difficult to get rid of.

________, today, more and more consumers are choosing “green” and demanding that the products they buy should be safe for the environment. ________ they buy a product, they ask questions like these: “Will this shampoo damage the environment?” “Can this metal container be ________ or can it only be used once?”

A recent study showed that two ________ five adults now consider the environmental safety of a product before they buy it. This means that companies must now change the ________ they make and sell their products to make sure that they are “green,” that is, friendly to the environment.

Only a few years ago, it was impossible to find green products in supermarkets, but now there are hundreds. Some supermarket products ________ labels to show that the product is green. Some companies emphasize that their products are clean and safe in their advertising and have made it their main selling ________.

The ________ for a safer and cleaner environment is making companies rethink ________ they do business. No longer will the public accept the old ________ of “Buy it, use it, throw it away and forget it.” The public ________ is still here, and companies are ________ their act gradually.

8 . Since 1960, considerable scientific researches have been done on chimps in their natural habitats. Astonishingly, scientists have found out that the social _________ of Chimps are very similar to humans. Chimps will _________ in certain ways, like gathering together to protect their land. But beyond the minimum requirements as social beings, they have little instinct (本能) to _________ one another. Chimps in the wild seek food for themselves. Even chimp mothers regularly _________ to share food with their children. Who are able from a young age to gather their own food?

In the laboratory, chimps don’t _________ share food either. If a chimp is put in a cage where he can pull in one plate of food for himself or, with no greater effort, a plate that also provides food for a neighbor to the next cage, he will pull _________ -he just doesn’t care whether his neighbor gets fed or not. Chimps are truly selfish.

Human children, _________, are extremely cooperative. From the earliest ages, they desire to help others, to share information and to participate in achieving common goals. The psychologist Michael Tomasello has studied this _________ in a series of experiments with very young children. He finds that if babies aged 18 months see a worried adult with hands full trying to open a door, almost all will immediately try to help.

There are several reasons to believe that the urges to help, inform and share are not taught, but naturally _________ in young children. One is that these instincts appear at a very __________ age before most parents have started to train their children to behave __________. Another is that the helping behaviors are not improved if the children are rewarded. A third reason is that social intelligence __________ in children before their general cognitive(认知的) skills, at least when compared with chimps. In tests conducted by Tomasello, the human children did no better than the chimps on the __________ world tests but were considerably better at understanding the social world.

The core (核心) of what children’s minds have and chimps’ don’t is what Tomasello calls shared intentionality. Part of this ability is that they can __________ what others know or are thinking. But beyond that, even very young children want to be part of a shared purpose. They actively seek to be part of a “we”, a group that intends to work toward a(n) __________goal.

9 . Wildlife has been greatly threatened in the modern age. There are species(物种) that are _______ every day. The white-naped crane is a typical example. So scientists are trying their best to _______ the species from going out of existence.

Chris and Tim work at a zoo, helping endangered cranes with their _______. Emma, a female crane, has been in their _______ since she arrived in 2004.

Born at an international crane foundation, Emma was _______ by human caretakers. This led to an unexpected _______, though she had a wonderful time there. Emma had _______ taken herself as a crane and become deeply attached to humans. She _______ to live with male cranes, and even had a _______ for killing some of them, which made it ________ for her to become a mother.

________, the two zookeepers didn’t want to see the extinction(灭绝) of this precious species. With their patience and efforts, they successfully developed a ________ of artificial breeding(人工繁殖) and natural reproduction. This ________ Emma to give birth to five baby cranes.

The two keepers are proud of their productive work. But before they can be ________, more efforts must be made, because the population of the crane in the wild is on the ________, and many other species appear headed toward extinction. ________, not everyone has realized that wildlife has thoughts, feelings, and most importantly, equal rights to survive.

How can we ________ the ever-widening gap that separates us from other animals? Chris and Tim offered us the ________: human beings took it for granted that their ________ held all the solutions, but maybe their hearts can be a better ________.