来自：查字典高考网 2014-12-25
question 41-50
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 extreme， 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 seawater is frozen， the dissolved materials are left behind. in this manner， seawater 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， off 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.
4l. what does the passage mainly discuss？
the elements of salt
the bodies of water of the world
the many forms of ocean life
the salinity of ocean water
42. the word this in line 5 refers to
ocean
evaporation
salinity
crystals
43. according to the passage， the ocean generally has more salt in
coastal areas
tropical areas
rainy areas
turbulent areas
44. all of the following are processes that decrease salinity except
evaporation
precipitation
runoff
melting
45. which of the following statements about the salinity of a body water can best be
inferred from the passage？
the temperature of the water is the most important factor.
the speed with which water moves is directly related to the amount of salt.
ocean salinity has little effect on sea life.
various factors combine to cause variations in the salt content of water.
46. the word altered in line 16 is closest in meaning to
determined
changed
accumulated
needed
47. the world it in line 18 refers to
sea ice
salinity
seawater
manner
48. why does the author mention the weddell sea？
to show that this body of water has salinity variations
to compare antarctic waters with arctic waters
to give an example of increased salinity due to freezing
to point out the location of deep waters
49. which of the following is not a result of the formation of ocean ice？
the salt remains in the water.
the surrounding water sinks.
water salinity decreases.
the water becomes denser.
50. what can be inferred about the water near the bottom of oceans？
【托福（TOEFL）考试阅读模拟试题（10）】相关文章：
[标签：海外留学,语言考试,托福,,]
2019全国高考志愿填报攻略 第50集 天津市高考历史三年本科录取排名
衍声高考琴行2019高本硕学生暑假音乐会 张俊瀚《陕北民歌主题变奏曲》《阿根廷舞曲》第三乐章
探秘历史 第二季 第479集 河南叛逆高考生，写下8000字批判作文，现状如何？
张雪峰高考志愿填报指南 第28集 高考志愿分析，材料科学与工程专业，就业很一般，建议慎重选择
你高考成绩高吗？这道题目怎能成立？高难度奥数，能不能把你难住
乾坤已定，组合解读2019高考数学全国3卷理科18题，你是黑马吗？
学渣儿子高考，英语选择题全选B！老师通报成绩的那一刻父亲懵了
一边扔试卷一边玩摇滚？这个学校的高考减压方式，真是帅到没朋友
