海水盐度如果我们分析海水的盐度，会发现地区间只有轻微的变化，然而有些小的变化是重要的。
导致海洋的盐度变化的基本过程有三个，其中之一是通过蒸发的方式即把液态水转化为水蒸气来减少海洋中的水分。
这样由于盐留了下来，所以盐度增大。
当然，如果这种方式走向极端，将会余下白色的盐晶体。与蒸发相反的是降水，如降雨，由此水被加入海中，海水被稀释，从而盐度降低。
这种情形会发生在大量降雨的地区，或江河入海岸处。因此，盐度通过蒸发减少水分而上升或通过降水或径流增加淡水成分而下降。一般来说，在阳光很
强烈的热带地区，海水的盐度略高于世界上其它没有热带那样多的蒸发的地区。同理，在江河稀释海水的海岸地带，海水盐度略低于其它海区。
第三个可以变更盐度的过程与海洋中冰的形成和融化有关。海水冻结时，溶于其中的物质被留了下来。这样，在新形成的海
水冰面的正下方的海水比在冰形成之前有更高的盐度。
当然，当冰融化的时候，会降低周围水中的盐度。
在南极洲边缘的威德尔海中，结冰过程增加低温海水的盐度，从而形成了浓度最大的海水。这些大密度的海水下沉，可以在世界海洋的深水域发现。
if the salinity of ocean waters is analyzed, it is found to vary only slightly from place to place. nevertheless, some of these small changes are important. there are three basic processes that cause a change in oceanic salinity. one of these is the subtraction of water from the ocean by means of evaporation--- conversion of liquid water to water vapor. in this manner the salinity is increased, since the salts stay behind. if this is carried to the etreme, of course, white crystals of salt would be left behind.
the opposite of evaporation is precipitation, such as rain, by which water is added to the ocean. here the ocean is being diluted so that the salinity is decreased. this may occur in areas of high rainfall or in coastal regions where rivers flow into the ocean. thus salinity may be increased by the subtraction of water by evaporation, or decreased by the addition of fresh water by precipitation or runoff.normally, in tropical regions where the sun is very strong, the ocean salinity is somewhat higher than it is in other parts of the world where there is not as much evaporation. similarly, in coastal regions where rivers dilute the sea, salinity is somewhat lower than in other oceanic areas.a third process by which salinity may be altered is associated with the formation and melting of sea ice. when sea water is frozen, the dissolved materials are left behind. in this manner, sea water directly materials are left behind.
in this manner, sea water directly beneath freshly formed sea ice has a higher salinity than it did before the ice appeared. of course, when this ice melts, it will tend to decrease the salinity of the surrounding water.in the weddell sea antarctica, the densest water in the oceans is formed as a result of this freezing process, which increases the salinity of cold water. this heavy water sinks and is found in the deeper portions of the oceans of the world.Zw5000.cOM
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春节 Spring Festival精选优秀英语作文
Every year, Spring Festival makes me happy, because I can spend a long holiday to stay with my families. On the New Year’s Eve, all the families got together. We woke up early in the morning and then my mother started to purchase some food to prepare the big dinner. I helped my mother to bring the food. Before dinner, there was a tradition in my hometown. We needed to bring the chicken to take a bow to our ancestors, showing our respect and gratitude. When the dinner’s ready, we ate happily and talked a lot. Then at night, the families pasted the New Year’s scrolls and decorated the house. What a harmonious environment and we enjoyed the family hour. In the next few days, I visited a lot of relatives. It was a good chance for us to communicate with each other.
每年春节我都很高兴，因为我可以有一个很长的假期可以和我的家人呆在一起。所有的家人都在除夕那天聚在一起了，我们一大早就醒了，然后我妈妈开始去买食物来准备晚餐。我帮我妈妈拿菜。在吃晚餐前，在我的家乡有一个传统，我们需要拿鸡去祭拜祖先，向他们展示我们的敬意和感激之情。晚餐准备好后，我们开开心心地吃，也聊得很开心。饭后，大家就一起贴春联装饰房子。这是多么和谐的环境啊！享受着家庭的时光。在接下来的几天里，我探望了很多亲戚，这是一个让我们彼此之间进行交流的好机会。
禁毒 Drug Control精选优秀英语作文
As the economy develops, most people have the incomes. For some children, their parents can provide them all the things they want. When people start to chase for more amusement, some of them cross the limited line and do the criminal things. Many young people have been reported to take drug in group. The bad guys try to control these young people, so they seduce them to take drugs to make more profit. It is very dangerous to have a taste of drug. Once people try, it is hard for them to get rid of it. The drugs only brings negative sides to people's life, some even to die for it. So a wise person will say no to drugs and the government has taken strict laws to control drugs.
随着经济的发展，大多数人都有着不错的收入，对一些孩子来说，他们的父母可以为他们提供他们想要的一切。当人们开始追求更多的乐趣时，一些人跨越了界限，做了一些犯罪的事情。据报道，许多年轻人都服用了药物。坏人试图控制这些年轻人，所以他们引诱他们吸毒，以此来赚更多的钱。碰毒品是很危险的，人们一旦尝试过，就很难摆脱了。毒品只会给人们的生活带来负面影响，有些甚至会为之而死亡。因此，一个明智的人会对毒品说不，而政府也已经采取了严格的法律来控制毒品。
