TPO 第26套 综合写作题目重新选题
阅读材料
收起The zebra mussel, a freshwater shellfish native to Eastern Europe, has long been spreading out from its original habitats and has now reached parts of North America. There are reasons to believe that this invasion cannot be stopped and that it poses a serious threat to freshwater fish populations in all of North America.
First, the history of the zebra mussel’s spread suggests that the invasion might be unstoppable. It is a prime example of an invasion made possible by human transportation. From the zebra mussel’s original habitats in Eastern Europe, ships helped spread it out along new canals built to connect Europe’s waterways. The mussel can attach itself to a ship’s bottom or can survive in the water—called “ballast water"—that the ship needs to take on to properly balance its cargo. By the early nineteenth century, the mussel had spread to the whole of Europe. It was later carried to the east coast of North America in the ballast water of ships traveling from Europe. The way ships have spread the zebra mussel in the past strongly suggests that the species will soon colonize all of North America.
Moreover, once zebra mussels are carried to a new habitat, they can dominate it. They are a hardy species that does well under a variety of conditions, and they have a high rate of reproduction. Most important, however, zebra mussels often have no predators in their new habitats, and species without natural predators are likely to dominate their habitats.
Finally, zebra mussels are likely to cause a decline in the overall fish population in habitats where they become dominant. The mussels are plankton eaters, which means that they compete for food with many freshwater fish species.
听力材料
收起写作题目
收起Summarize the points made in the lecture, being sure to explain how they support/contradict specific points made in the reading passage.
答题辅导
收起1.阅读要点概括:
Theme:
The unstoppable invasion from ZM will lead to serious impact on native fish
Key point 1:
Owing to ships, ZM will quickly take overall the habitats in North America
Key point 2:
ZM can dominate the new habitats thanks to high productivity and no predators
Key point 3:
ZM’s competition on food with native fish species will lead to decline in fish population
2.听力要点概括:
Theme:
Ways to control, not clear
Key words 1:
Enough knowledge, stop, empty out the freshwater, refill with ocean water, saltwater, kill
Key words 2:
Beginning, birds, notice, new food source,change, eat a lot
Key words 3:
Overall population, decrease, other fish,positive impact, generate nutrients, increase