Shenzhen's fast development has made it become China's most crowded city!  Here are about 15 million people living on its 1,991 square kilometers. On each square kilometer averagely(平均地) live 7, 500 people. It is 1, 080 more than that in Hong Kong, and nearly 800 more than that in Guangzhou.

    Besides, Shenzhen owns 2 million local vehicles, and about 300, 000 vehicles from other places also run on the local roads every day. The total length of the city's roads is 6, 041 kilometers. It means each resident only owns 0. 58 meters of road!

    As a result, the city is facing serious environment and resource(能源) problem. One of the problems is water shortage. The amount of fresh water for each person of the city is only 25％ of the country's average. What's more, most of the water drunk by Shenzhen people comes from other areas.

    Gift giving is different from culture to culture and person to person.

    When giving gifts, sometimes color is important. For example, for many Chinese people around the world, red is a lucky color, and people often like to pack gifts in this color. However, did you know that in Korea, red is a color of death? That is why you should not pack gifts in this color if you are giving a gift to a Korean person.

    What about western countries? In western countries, the color of packing paper is not really important. But color does matter when giving flowers, especially roses. You should not give red roses to a western person you don't know very well because they are a symbol of love. You could give yellow roses instead as these are a symbol of friendship. You could also send pink roses as gifts to say thank you.

    What other things should you remember when giving gifts to someone from a different culture? Well, one thing you should keep in mind is the person's religion. When choosing a gift for a Muslim or Jewish friend, you should never get good food including pork or things made from pigskin. Another thing that you shouldn't get for a Muslim person is alcohol.

    If you meet a British person in the street, it is very likely that he or she will apologize whether it is his or her fault（过错） or not.

    It seems that Britain is becoming a nation where everyone is saying sorry. Almost each person says sorry about eight times each day-and one in eight people apologize as many as 20 times a day.

    As you may have seen, the British apologize more often than members of other cultures. A research shows that in many cases, people's love of saying sorry in Britain goes a little further than it does for Americans. For example, about 15 British people would say"sorry" while only 10 from the[US would do this if they sneezed, if they corrected someone's mistake or if someone knocked into them.

    In the old days, "sorry" was used to express regret and sadness for having done something wrong. But now British people use the expression as a way of showing good manners. For example, they might say "sorry" instead of "excuse me", "pardon", "what" or "whatever".

    People in Britain also use sorry when they share the same feeling with others-so they might say "sorry about the rain".

    However, British people's use of "sorry" may make things very confusing（迷惑不清）and difficult for foreigners who are not familiar with their ways. But actually, people in Britain pay much attention to the feelings of others. This is the very reason why they apologize every t day.

    Mothers Day is a celebration in memory of mothers. It celebrates the importance of mothers in society. It is celebrated on different days in many parts of the world, mostly in March, April or May. Let's see how different people celebrate their Mother's Day.

    Mexico(May 10)

    Children make gifts and give them to their mums on Mother's Eve (May 9).On the morning of May 10,families make a special trip to church and cat tamales(玉米饼),sometimes filled with meat, cheese or vegetables.

South Africa(Second Sunday of May)

    Besides giving mums Mother's Day cards, people show their thanks for their mothers by wearing red and pink flowers called carnations. If their mothers have passed away, they wear white carnations.

    United Kingdom(Fourth Sunday of Lent(大斋期))

    Mother's Day is a traditional day for people to visit their hometown and attend their home churches. People also bake(烘焙)special fruitcakes to give to their mums.

    Indonesia(December22)

    People throw big parties for their mums, filled with fun activities-such as cooking competitions and kebaya-wearing competitions!(A kebaya is a traditional blouse and skirt.)