When Juliet was a child, she often went to the city park and played with her friends. On a Saturday morning, when Juliet came to the park with her mom, she looked around and felt very ________.

“What’s the matter, dear?” asked her mom. Juliet said, “Mom, how beautiful and ________ the park was before! But now there’s so much ________ on the ground.” Juliet’s mom looked around. There were pieces of paper, boxes, glass bottles everywhere.

“What can we do?” asked Juliet ________. “I’m sure you will think of something.” said her mom.

As soon as Juliet and her mom went home, Juliet painted a picture of the park and wrote a sign in big ________ at the top of the picture. The sign read “PLEASE KEEP OUR PARK CLEAN”. Later, she ________ many bags and went back to the park with her mom. Juliet put up her picture on a big rubbish can (垃圾桶). “Will you ________ the rubbish with me, mom?” Juliet said as she handed her mom a bag. “I surely will” said her mom with a big smile.

The children at the park ran over to ________ what was going on. Juliet handed them each a bag. “Let’s clean this place up.” said Juliet. Then they began to pick up the rubbish, talking and laughing. Soon all the bags were ________.

“We need to come back another day. There’s still some rubbish on the ground, but the ________ looks much better,” said Juliet. Her mom said, “So it does. I’m proud of you. I knew you would   think of a way to help.”

【推荐2】What does the word ecology mean? It was invented by Emst Hacckel, a German biologist. He joined two Greek ________: oikos, meaning “house”, and logie, meaning “the study of”. Together they mean “the study of the house”. The “house” Haeckel had in mind is our ________, Earth. Earth is home for all living things—humans, animals, plants, and even ________ microbes (微生物). An ecologist is a scientist who studies the relationships between organisms (生物) and their environment. It may include water, gases, rocks, and ________. Ecologists also study the balance of using the environment ________ protecting it. An ecologist ________ asked a boy what he thought it meant to protect the environment. The boy said, “You go into the ________ and look for somebody who wants to cut down a tree. You ________ his axe (斧头). You tell him about how important trees are.” “Good answer,” said the ecologist, “but it may not be ________ to find a woodcutter to talk to. Also, remember that sometimes it’s ________ to cut down a tree. If we cut down too many trees, the forest will ________. If we don’t cut down any trees, we won’t get any resources (资源) ________ the forest. We have to find the right balance” “I get it,” the boy said. “We need the forest’s resources for wood and paper ________ we might not have desks or notebooks for school.” “________, school is a good place to learn about ecology,” added the ecologist, “Then you will know ________ to protect the natural environment.”

Natural resources (自然资源) are things that we use that come from Earth. Our natural resources are limited. This means that they will not _________ forever. Some are renewable (可再生的), like when you plant a new tree when you _________ one down. Others are not renewable, like when you dig coal out of the _______. Once it is used, it is gone.

People realize the ________ that Earth’s natural resources are limited, and can do things to help conserve (节约) those resources. _________ you try to conserve a natural resource, you try to use less of it, so it does not get used up so __________. One way that people conserve fuel, like gasoline, is by riding a bicycle or walking when the __________ is short instead of driving everywhere.

Water is a very important natural resource because we all need it to stay _________. We can conserve water ___________ making sure that our pipes and taps do not leak (漏). We can also make _________ choices to conserve water, like only using the dishwasher or washing machine when they are full. Eevryone can make contributions to protecting natural resources.