Brain fitness has basic principles：variety and curiosity. When anything you do becomes second nature，you need to make a change.If you can do the crosswords（纵横字谜）in your sleep，it’s time for you to move on to a new challenge in order to get the best workout for your brain. Curiosity about the world around you，how it works and how you can understand it will keep your brain working fast and efficiently.【小题1】

Play Games

Brain fitness programs and games are a wonderful way to tease and challenge your brain. Sudoku，crosswords and electronic games can all improve your brain’s speed and memory. These games rely on logic，word skills，math and more.【小题2】 You’ll get more benefit by doing these games a little bit every day—spend 15 minutes or so，not hours.

Think Deeply

Thinking deeply every day is perhaps the single greatest thing you can do for your mind or body health.【小题3】

Eat for Your Brain

【小题4】 Focus on fish oils from wild salmon（鲑），nuts such as walnuts，seeds such as flaxseed and olive oil. Eat more of these foods and less fats. Remove trans fats（反式脂肪）completely from your diet.

【小题5】

Stories are a way that we strengthen memories，explain events and share moments. Practice telling your stories，both new and old，so that they are interesting，attractive and fun. Some basic storytelling techniques will go a long way in keeping people’s interest both in you and in what you have to say.

   Good learners can inspire students or anybody to learn well. Here are some characteristics of good learners.

Good learners are curious. They wonder about all sorts of things，often about knowledge beyond their areas of expertise（专长）. 【小题1】 Finding out about something they didn't know satisfies them for the moment，but their curiosity is addictive.

Good learners don't give up easily. A few things may come easily to learners but most knowledge arrivesafter effort. Good learners are willing to put in time. They try to search out new information. They read，analyze，and evaluate（评估）the information they've found. 【小题2】

Good learners know that a lot of learning isn't fun. The journey to understanding generally isn't all that exciting. 【小题3】 Others need boring attention to detail，and still others need periods of intense mental focus. Your back hurts，your arms and legs get tired，and your coffee gets cold.

【小题4】 There's always more to know. Good learners are never satisfied with how much they know about anything. They are surrounded by questions — the ones they still can't answer, or the ones without very good answers. Those questions follow them like day follows night with the answers bringing daylight.

Good learners share what they' ve learned. Good learners are teachers committed to sharing with others what they' ve learned. 【小题5】 Good learners can also explain what they know in ways that make sense to others. They are connected to the knowledge passed on to them and committed to leaving what they' ve learned with others.

   Many people would like to change various things in their life in order to be more eco-friendly. 【小题1】 They range from changing their jobs to their vehicles and even their homes. In what follows, I am going to talk about the most energy-efficient（节能的）small green homes. Keep on reading, as this article is very useful if you would like to change your home into a more eco-friendly one.

【小题2】 This happens because a green home will contain green devices（设备）which need alternative sources of energy such as solar power and wind power. They do not pollute the atmosphere as much as the regular sources of energy. 【小题3】 The process of installing them is kind of expensive but in the long term, it will save you a lot of money.

【小题4】 It will be made out of recyclable and renewable materials. For example, the furniture will be made out of bamboo instead of materials which take years to grow. This means that there is not a risk of them to be used up as in the case of certain types of wood or other materials.

A green house will be decorated by using non-toxic（无毒的）materials. 【小题5】 They contain harmful chemicals which can be dangerous, but the most energy-efficient small green homes do not have this problem.

   In the United States alone,over 100 million cell-phones are thrown away each year.Cell-phones are part of a growing mountain of electronic waste like computers and personal digital assistants.The electronic waste stream is increasing three times taster than traditional garbage as a whole.

Electronic devices contain valuable metals such as gold and silver.A Swiss study reported that while the weight of electronic goods represented by precious metals was relatively small in comparison to total waste,the concentration（含量）of gold and other precious metals was higher in So-called e-waste than in naturally occurring minerals.

Electronic wastes also contain many poisonous metals.Even when the machines are recycled and the harmful metals removed,the recycling process often is carried out in poor countries,in practically uncontrolled ways which allow many poisonous substances to escape into the environment.

Creating products out of raw materials creates much more waste material,up to 100 times more,than the material contained in the finished products.Consider again the cell-phone,and imagine the mines that produced those metals,the factories needed to make the box and packaging（包装）it came in.Many wastes produced in the producing process are harmful as well.

The U.S Environmental Protection Agency notes that most waste is dangerous in that"the production, distribution,and use of products-as well as management of the resulting waste-all result in greenhouse gas release." Individuals can reduce their contribution by creating less waste at the start-for instance,buying reusable products and recycling.

In many countries the concept of extended producer responsibility is being considered or has been put in place as an incentive（动机）for reducing waste.If producers are required to take back packaging they use to sell their products,would they reduce the packaging in the first place?

Governments' incentive to require producers to take responsibility for the packaging they produce is usually based on money.Why,they ask,should cities or towns be responsible for paying to deal with the bubble wrap（气泡垫）that encased your television?

From the governments' point of view,a primary goal of laws requiring extended producer responsibility is to transfer both the costs and the physical responsibility of waste management from the government and tax-payers back to the producers.