2017年4月1日托福真题回忆及pdf下载

　　2017年4月1日托福真题回忆

　　2017年4月1日托福真题回忆-Reading

　　Passage 1

　　Topic：Jellyfish

　　Content Review

　　第1段：Whether we should worry about the increasing jellyfish population. On the one hand, prey population increases and water temperature changes; on the other hand, it occurs in many places. Then take Japan as- example, whose jellyfish population drifted to the sea has raised up to 500 million each day.

　　第2段：指出导致jellyfish population增加的因素，其一是人们对seafood的喜爱导致overfishing，使得predator的数置减少。

　　第3段：指出另一个因素是jellyfish's thrive features: global warming and acidification.

　　第4段：海水富营养化。

　　第5段：Other aquatic life forms cannot exist，但是 jellyfish有几个特征使得其能生存: good survival rates, rapid reproduce and low oxygen level.

　　第6段：benefits from globalization.

　　Passage 2

　　Topic：美国早期的邮递业

　　Content Review

　　第1段：America formation promotes circulation of news and information, both velocity and volume, people trades with one another in distance.

　　第2段：The United States Post Office makes news circulation easy and free.随后介绍了two decisions that help postal system to improve integrate nation: one is post office is granted to sell all the newspapers at low price, another is Congress never turning down any petition for new road or new post service.

　　第3段：提出虽然post service由political purpose决定，但是它也影响了business，举了wheat的例子。

　　第4段：transportation improvements, new built roads提高了mail service的capacity and speed up service, too.随着交通发展，越来越多的方式can deliver mails: sailing ship, stagecoach, steamboat, canal, boat and railroad.

　　Passage 3

　　Topic：Green Revolution

　　Content Review

　　第1段：The green revolution can date as far back to 1930s.农业科学家做实验以manipulate the seed of crops to improve productivity.随后指出科学家把中国大米和印度大米作为parents研究出IR8，优点是bigger head of grain and stronger stem.虽然IR8提离了产量，但是科学家仍然不满足，于是研究出了IR36，优点是：来自13个parents (母本)，可以抵抗15种pests, 110 days of growing period and three crops each year。

　　第2段：global hunger makes the green revolution extraordinary. India can be self-sufficient in crop production and Asia increases the crop production.

　　第3段：非洲的地理环境使得其受益较小，故科学家研发出新的super rice, which can be transplanted that depended on seeding directly instead of seedling.

　　第4段：指出the green revolution有很多detractors，比如chemical fertilizers and pesticides can reduce the organic matter in the soil, and many small-scale farmers lack of financial resource to purchase genetically enhanced seeds.

　　Passage 4

　　Topic：鸟类进化

　　Content Review

　　第1段：指出all bird groups are classified as Neornithes,科学家使用K-T extinction作为新旧鸟类的dividing line.

　　第2段：传统认为modern birds起源于Cenozoic.

　　第3段：指出有新的研究利用molecule time estimation得出modem birds实际上起源于Cretaceous.

　　第4段：指出尽管molecule time estimation是根源于gene sequence，但是不能解释导致mass extinction产生的evolution process.