求Tpo23 综合写作范文。谢谢。

求Tpo23 综合写作范文。谢谢。

TPO 23 Sample Answer
　　The reading and listening materials have a debate on why yellow cedars are in decline. The passage puts forward three hypotheses to explain this phenomenon， which are contradicted by the lecture.
　　First， the writer suggests that insect parasites are the culprit of the lessening population of the yellow cedars by raising the example of cedar bark beetles. However， the speaker says that this explanation does not hold water， for the reason that healthy yellow cedar is more resistant to cedar bark beetles because of powerful poisonous chemicals. For those dead yellow cedars with the infection of the insects， they may be already damaged. As a result， insect parasite is not responsible.
　　The second hypothesis the writer comes up with is that brown bears feed on yellow cedar bark， which gives rise to the decline. However， the speaker does not think so. In fact， across the northwestern coast of North America， the total number of yellow cedars has been dropping， both on the mainland and on the islands just off the coast. There are no bears on the islands， yet the cedars on islands are still in decline. So bear should not be to blame.
　　The third theory offered by the writer is that the frozen root damage caused by climate change should take the responsibility for the diminishing population of the yellow cedars. However， the speaker believes that this explanation does not bear much analysis. According to the speaker， more trees are dying in the relatively warmer lower elevations than in the higher elevations. Since the weather in lower elevations tends to be warmer， the frozen root theory is unlikely to hold water.