下面是范文网小编分享的实用的大学英语作文400字3篇(大学英语作文400词左右带翻译)，欢迎参阅。
实用的大学英语作文400字1
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。
实用的大学英语作文400字2
firstly,i decide to try my best to learn english .because my english so poor that it affects my other subject.i willface many differences ,such as broadening my vocabulary, training my listening ,improving my write and so on. i must work hard because i dont want to behind the times.
secondly ,i will give up watching football games because every time it takes me two hours ,which makes me not finish my homework .as a student ,study is our duty ,so i wii focused more on study and less on playing . in order to my future ,i will work hard.
实用的大学英语作文400字3
do you know how penitent the disabled kids are? can you imagine what life they are living? do you know what challenges they have to facing?
the summer holiday is coming. the students union is going to organize an action in order to help the disabled kids.
we are planning to go to the hospital to take good care of the children. were also going to the low income families to help them to improve their living standard.
now we are recruiting the volunteers.
our activity is from july 1 to august 30. if you are not busy during the vocation and you love the kids, just join us.
if any questions, connect with our president jenny. the telephone number is.