The word “day” has two meanings. When we talk about the number of days in a year, we are using “day” to mean 24 hours. But when we talk about day and night, we are using “day” to mean the time between sunrise and sunset. Since the earth looks like a ball, the sun can shine on only half of it at a time. Always one half of the earth is having day and the other half night. A place is moved from day into night and from night into day over and over by the spinning（旋转）of the earth. At the equator（赤道）day and night are sometimes the same length（长度）. They are each twelve hours long. The sun rises at 6 o'clock in the morning and sets at 6 o'clock in the evening. For six months the North Pole（北极）is tilted（倾斜）toward the sun. In those months the Northern Hemisphere（半球）gets more hours of sunlight than the Southern Hemisphere（半球）. Days are longer than nights. South of the equator nights are longer than days. For the other six months the North Pole is tilted away from the sun. Then the Southern Hemisphere gets more sunlight. Days are longer than nights. North of the equator nights are longer than days. Winter is the season of long nights. Summer is the season of long days.

    Do you think you're green? You're a totally modern citizen, aren't you? You keep your bottles and take them to the bottle bank. You have a black bin and a green bin, one for general waste and one for recyclable waste. Your car uses lead—free petrol. You use the same plastic bag every time you go to the supermarket. Maybe you even cycle to work from time to time. You are playing your part; you are green and environment—friendly. Well, I've got news for you:

    YOU ARE NOT DOING ENOUGH!

    If you don't believe me, look at these facts. Trust me, they're from a BBC website.

    On average every person in the UK throws away their own body weight in rubbish every seven weeks.

    Every year, the average dustbin contains enough unused energy for 500 hot baths, 3,500 hot showers or 5,000 hours of television.

    Every UK household produces over one tonne of rubbish every year.

    If all the aluminium drink cans sold in the UK were recycled, there would be 14 million fewer full dustbins per year.

    Just one recycled aluminium can saves enough energy to run a television for three hours!

    At Christmas over 83 square kilometres of wrapping paper is thrown in the bin.

    Almost three billion nappies (used for baby) are thrown away in the UK every year. 90% of these are buried and take hundreds of years to disappear.

    Have I made you believe that you need to do more? No? OK, here are one or two more facts.

    Recycling just one plastic bottle saves enough energy to power a light bulb for six hours.

    Collecting dustbins and cleaning streets costs ￡1. 6 billion per year.

    Surely you must believe me now. You need to do more. The good news is that there is some— thing else you can do.

    The spring season brings warm weather, flowers and other changes for people to enjoy. For some restaurant cooks, the most exciting spring arrival is ramps.

    Ramps are a wild plant in the eastern mountains of North America. They are one of the first plants that grow in the spring, usually between April and May. They are recognized(意识) by their red stem(茎), and two long and wide green leaves. They are also famous for their strong taste, similar to onions(洋葱).

    Ramps are not as well-known as other vegetables, but they have a long history in the United States. In the Appalachian Mountains, ramps have been an important food for a longtime. During spring, it is common for small towns in the Appalachian area to hold large ramp dinners for the community.

    However, over the last 30 years, ramps popularity has grown quickly. They are now a highly-desired vegetable for many nice restaurants in cities like New York and Washington D.C.

    One reason the plant is popular is that it grows in the wild. It is difficult to grow them on farms. Most restaurants get them from foragers, who collect ramps by searching forests for some small pieces of land where they grow. Ramps have a short season. Within a few weeks of full growth, the plant is done for the year. This shot life is some reason for their popularity.

    And that popularity could lead Io their disappearance from Earth. In 1995, the local government in Quebee, Canada, stopped people selling the plant to businesses in order to protect the plant against being over-dug.

    The season is short, but it has not ended yet. If you are in the right place, you still have time to try a taste of ramps yourself.

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    The largest animal ever to live on Earth is the blue whale. It weighs about 80 tons--more than 24 big elephants. It is more than 30 metres long. A new baby whale weighs as much as a big elephant.

    Cats won't die if they fall off very high places because they can turn themselves up the right way so as to keep their bodies safe. One cat fell off 32 floors onto the street, but it was just hurt a little.

    A bear can run as fast as a horse.

    A new-born panda is smaller than a mouse and weighs about 100 grams.

    Elephants are the most careful animals in their love. A male elephant may show his lady love for up to three years until the female elephant takes his love. They often show their love by touching each other's body.

    Usually, wolves do not hurt people. For years a Canadian newspaper says that they would give anyone a lot of money if he or she could show that a wolf could hurt a person. But nobody could do that. Wolves do not usually go together though they may do this in winter and they only hurt people at an unusual time.