1 . 为了缓解学习压力，你校将于本周末组织一次游览长城的徒步旅行。请你写封倡议信，刊登在校英语报上，动员大家积极参与，内容包括:
1.活动目的;
2.徒步旅行的益处和注意事项;
3.发出倡议。
注意: 1.词数100左右;
2.可以适当增加细节，以使行文连贯。

2 . Pollution

Pollution happens when the environment is dirtied, by waste, chemicals, and other harmful substances(物质).Pollution is a problem all over the world. But it is especially bad in large cities with a lot of industries and cars.    1    

Wildfires, volcanoes, and industrial chemicals cause some air pollution. But most air pollution comes from burning fossil fuels (矿物燃料）These include coal, oil and natural gas. The burning of fossil fuels may release harmful gases. Air pollution may cause such diseases cancer and asthma. It also leads to polluted rain that can harm living things    2     Finally, air pollution damages the ozone layer(臭氧层)which is important because it protects Earth against harmful rays from the sun.

Causes of water pollution are easy to see. People dump(倾倒) garbage and dirty water into river, lakes and oceans. Factories or cities sometimes release poisonous chemicals, and other wastes into water. These chemicals may make the groundwater unfit to drink.    3    

Littering, or throwing garbage on the ground, is a form of land pollution. Litter can destroy the habitats of plants and animals. The buildup of dangerous chemicals in the ground is another form of land pollution. The chemicals may come from farms or factories.    4     They may even harm people who eat the polluted plants and animals.

Many governments, environmental groups, and ordinary people are working to control pollution. Governments have passed laws to keep people from releasing dangerous chemicals into the environment     5     Instead they are getting power from the sun, wind, water, and other energy sources to produce less pollution. Many communities use recycling to reduce pollution.

A．Farmers use chemical to help crops grow.

B．This type of pollution may be seen in big cities.

C．They also can harm fish and other forms of life.

D．These chemicals can spread to plants and animals.

E．In addition, air pollution may be a cause of global warming.

F．There are three main forms of pollution: air, water, and land.

G．Some companies and people are trying to use fewer fossil fuels.

3 . A robot created by Washington State University (WSU) scientists could help elderly people with dementia (痴呆) and other limitations live independently in their own homes.

The Robot Activity Support System, or RAS, uses sensors installed in a WSU smart home to determine where its residents are, what they are doing and when they need assistance with daily activities. It navigates (定位) through rooms and around obstacles to find people on its own, provides video instructions on how to do simple tasks and can even lead its owner to objects like their medication or a snack in the kitchen.

“RAS combines the convenience of a mobile robot with the activity detection technology of a WSU smart home to provide assistance in the moment, as the need for help is detected,” said Bryan Minor, a postdoctoral researcher in the WSU School of Electrical Engineering and Computer Science.

Currently, an estimated 50 percent of adults over the age of 85 need assistance with every day activities such as preparing meals and taking medication and the annual cost for this assistance in the US is nearly $2 trillion. With the number of adults over 85 expected to triple by 2050, researchers hope that technologies like RAS and the WSU smart home will relieve some of the financial strain on the healthcare system by making it easier for older adults to live alone.

RAS is the first robot researchers have tried to incorporate into their smart home environment. They recently published a study in the journal Cognitive Systems Research that demonstrates how RAS could make life easier for older adults struggling to live independently.

“While we are still in an early stage of development, our initial results with RAS have been promising,” Minor said. “The next step in the research will be to test RAS’ performance with a group of older adults to get a better idea of what prompts, video reminders and other preferences they have regarding the robot.”

1. How does RAS serve elderly people?

A．Through sensors.	B．Through objects.
C．Through a mobile robot.	D．Through their daily activities.

2. What can we know about RAS?

A．It is the first robot used in daily life.	B．Its function remains to be tested.
C．It can locate people and do any task.	D．It can cook for owners on its own.

3. What’s Minor’s attitude toward the future of RAS?

A．Doubtful.	B．Negative.
C．Optimistic.	D．Uncertain.

4. What can be a suitable title for the text?

A．Elderly people leave the nursing home.

B．Smart Home Tests first elder-Care robot.

C．RAS, the first robot to make home smart.

D．Older adults have benefited from RAS.