閱讀主要觀點(diǎn)提?。?/p>
總論點(diǎn):歐洲鰻魚(European eels)最初生存在馬尾藻海域,洋流將它們帶到北太平洋海域。但是它們在繁殖期會重新回到馬尾藻海域進(jìn)行繁殖。19世紀(jì)70年代以后,有幾個原因可能導(dǎo)致了它們數(shù)量的急劇減少。
原因一:歐洲河流中用于發(fā)電的水壩。水壩會阻擋鰻魚游到可捕食的地區(qū),因?yàn)楹芏圉狋~沒到成年就死了。并且,從經(jīng)濟(jì)的角度出發(fā),不可能將用于發(fā)電的水壩撤掉,因而鰻魚的數(shù)量持續(xù)在減少。
原因二:19世紀(jì)80年代,歐洲爆發(fā)的寄生蟲導(dǎo)致了鰻魚的死亡。鰻魚吃了那些感染了寄生蟲的魚而大面積死亡。被寄生蟲感染程度的不一樣,不同地區(qū)鰻魚死亡的比例也不一樣。然而,究竟如何防治這種感染還是未知的。
原因三:受馬尾藻海域具體情況的影響。因?yàn)楹茈y定位鰻魚具體繁殖的地點(diǎn),所以究竟是什么原因?qū)е脉狋~數(shù)量減少以及應(yīng)該如何防護(hù)就不得而知。
聽力主要觀點(diǎn)提?。?/p>
總論點(diǎn):科學(xué)家已經(jīng)找到這幾個問題的解決方法。
方法一:可以沿著水壩的一側(cè)安裝一種空裝滿水的管道,這樣幼小的鰻魚就可以順利通過水壩并成功覓食。這樣遷徙就不成問題了。
方法二:那些容易感染寄生蟲的鰻魚是比較胖的鰻魚,它們吃了很多被寄生蟲感染的魚。既然我們得知感染寄生蟲的原因是飲食習(xí)慣,那么我們只需要將鰻魚轉(zhuǎn)移到那些無法吃到太多魚的水域就可以了。
方法三:現(xiàn)在有一種小型的設(shè)備可以安裝在鰻魚身上,追蹤它們在水里的位置。科學(xué)家將這些設(shè)備裝在鰻魚身上,當(dāng)鰻魚游回馬尾藻海域時,這些設(shè)備就被解除,并被收集起來。這樣就可以得知它們具體的遷徙路線及具體的繁殖地點(diǎn),以便清除繁殖地有可能對它們造成危害的因素。
新托福綜合寫作范文:
The writer explains three factors which have caused the decline of European eels. However, the professor says that each of the issues can be solved.
First, the professor states that the problem of the dams which block the eels’ migration route can be solved by engineers. The engineers can design structures consisting of a series of hollowed tubes built along the sides of dams. Then the baby eels can swim up those tubes which are filled with water and reach their feeding ground.
Second, the reading points out that it is the parasitic worm spreading to Europe in 1980s that causes the decline of eels. On the contrary, the professor proposes that the problem can be fixed too. Scientists have found that the most seriously infected by the parasites are the fattest eels which consume large amount of fish. So it is the eating habits and the eating opportunities of eels that determine the spread of the infection. Being aware of this, we can solve the problem by moving eels into areas where they can not eat so mush fish.
Third, the writer states that the difficulty of locating eels’ breeding area is the main obstacle to protect them. The listening, in contrast, presents that scientists can locate eels’ breeding area by attaching electronic device on them. Scientists can get data from the devices to the exactly locate their breeding grounds and then figure out the problem in their breeding area.
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