What can we do with mobile payment apps? Pay for everything that we want! That's true. These apps have made it much easier for us to ______. Over the past years, they have ______ changed the way business is done.

Now, some of these apps are trying to do more. One ______ is Alipay (支付宝). The ______ behind it, Ant Financial, is using the app to “build” a greener world. In 2016, it ______ the Ant Forest program. ______ is one of the world's first digital projects to “green” users' behavior.

Ant Forest simply makes living a low-carbon (低碳的) lifestyle fun. More than 300 million people have joined the program. Users who perform low-carbon activities, ______ paying bills online and walking to work, are given “green energy” points. When users have ______ points, Ant Financial will plant a real tree. Those who ______ try to collect more green energy can plant more trees. So far, more than 55 million ______ trees have been planted.

Xie Mingwu is the director of a forest workstation (工作站) in Inner Mongolia (内蒙古). He said Ant Forest brought ______ to local deserts. Since the start of the project, millions of trees have been ______ in Inner Mongolia.

Ant Financial has decided to spend more money and effort on Ant Forest. ______ the 300 million users continue to grow “trees” actively,   4,000 km² of forests will be created over the next five years. Ant Forest simply gives all of us a ______ to save the Earth. ______ it simply shows the amazing power of ordinary people. If many of us work together, we can make a contribution to making the world greener and more beautiful.

We are beautiful red-crowned cranes. We have red caps on _________ of our heads. You may think the _________ are our feathers. In fact, they are combs（冠）. We are one of the largest birds in size in the world. We are the _________. A red-crowned crane can weigh 11 kilograms when it _________. We’re good at dancing. I think we are the most beautiful _________ of all the birds. We are also good singers. We sing loudly and _________. We are good at flying _________. We fly to East Asia when warm _________ comes. We give birth to baby cranes there. We like to live together on wetlands in South-west China and some other places. We live mainly _________ worms（虫子）and small fish. We like to live in long grass. Water and grass are really __________ for us. However, life is __________ these years. We are one of the most endangered birds in the world now. People keep taking our living areas __________ make farms and build houses. __________, we don’t have much living space. And we don’t have __________ food to feed our babies because people fish and hunt too __________. Can you help me?

Yours sincerely,

Red-crowned cranes

A theme park in France set up a special and environmentally-friendly（保护生态环境的）way of keeping its ground free of trash. It ______ and trained six clever crows to pick up trash and keep the park clean. Crows are a kind of ______ and are about 47cm high. The clever birds will work for Puy du Fou theme park in the west of France. Workers ______ them to pick up cigarette ends, paper and other things people ______ on the ground. The birds pick up the trash and put it into a special rubbish bin, and then workers give out some bird ______ as a prize. The more trash the birds put on the rubbish bin, the more food they get.

The head of the theme park, Nicolas de Villiers, explained the reason ______ they use the birds to the reporters. He said there were several reasons for using crows. He said, “The goal is not to clean up, because the visitors are usually ______ to keep things clean, but also to show that nature itself can teach us to take care of the ______.” Crows are clever birds. Some biologists say they are as ______ as a seven-year-old child. Mr. De Villiers said, “In a supportive situation, they like to ______ with humans and set up a good relationship.” The crows are speedy workers and can fill a rubbish bin with rubbish in less than 45 minutes.”