【正文】 ple consequently Another difference among the world’s seas and oceans is that the salinity varies in different climate zones. , the Baltic Sea（波羅的海） in Northern Europe is only onefourth as saline as the Red Sea in the Middle East. There are two reasons for this. , in warm climate zones, water evaporates rapidly: therefore, the concentration of salt is greater. Second, the surrounding land is dry and, , does not contribute much fresh water to dilute the salty sea water. In cold climate zones, , water evaporates slowly. , the runoff created by melting snow adds a considerable amount of fresh water to dilute the saline sea water.Part IV Reading for Better Writing (20%)Passage OneDirections: Read the following paragraph, find out the topic sentence and then identify the irrelevant sentences. Mark the corresponding number on the below. (5’)① Different people spend their weekends in different ways．② Some enjoy going to the mountains to hike, ski or just relax．③ Water skiing is much more difficult than snow skiing．④ Others prefer going to the beach to enjoy the seashore activities and to get a suntan．⑤ Some of these people work very hard during the week；others have rather relaxing jobs．⑥ Still others like to relax by staying home and reading a good book．Topic Sentence：________Irrelevant Sentences：________________ Passage TwoDirections: In the following paragraph the topic sentence is absent, read them and write an appropriate topic sentence in your own words on the underline. (5’) It can affect us physiologically. Exciting music can increase our heart rate, our breathing, and our blood pressure. Calming music can relax our muscles and even lower our skin temperature. Music can affect us physically too. Everyone has found themselves tapping their feet or wanting to get up and dance to their favorite song. Music can definitely affect our mood and emotions. Music is slow and quiet makes us feel relaxed and less stressed, and stimulating music can energize us and make us feel playful and alive.Passage ThreeDirections: Rearrange the following sentences so that they will read logically. Put the letters in proper sequence in the boxes provided below.. (2’x5=10’)[A] Imitative words are words that sound like the thing or action they stand for.[B] The other one fifth is made up partly of borrowed words and partly of three other kinds of words: words from the names of peoples and places。歲月是有情的，假如你奉獻(xiàn)給她的是一些色彩，它奉獻(xiàn)給你的也是一些色彩。