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,,]
高考前必听的5首励志歌曲，《Dream it possible》最能鼓舞人心！
葛军大爷怒了：高考我出了个小学数学送分题，你们跟我说不会做？
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
amc传媒音乐影像 第一季 第600集 高中校长演唱《记忆花园》为高考学子助力打气
高考阅卷名师给考生的高考作文密训课 第3集 高考作文审题实操方法精讲（一）
1000张学生用草稿纸考研专用免邮空白便宜薄演草演算纸白纸本书写纸批发打草a4大张实惠装18k高考数学草稿本
高中语文知识清单高考语文总複习工具书第5次修订五全綵版五三曲一线科学备考基础知识手册知识大集结资料书参考书导书高一高二高三
