The reading and listening materials have a conflict of opinions about the decline in yellow cedar. The passage puts forwardthree reasons to explain this phenomenon,which are contradicted by the lecture.
First explanation brought up by the writer is that insect parasites are the culprit of the lessening population of the yellow cedarbyraising the example of cedar bark beetles. However, the speaker says that this explanation does not hold water, for the reason thathealthy yellow cedar is more resistant tocedar bark beetles because ofpowerful 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 a possible reason/ is a scapegoat.
culprit/scapegoat
Second supposition introduced by the writer is that brown bears feed on yellow cedar bark, which makes it a responsible/contributory factor. 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 islands cedars are still in decline. So bear is unlikely to be the culprit.
Third theory the writer comes up with 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 more analysis. According to the speaker, more trees are dying in the relatively warmer lower elevations than in the high elevations. Based on this fact, the root sensitivity that stems from the temperature changes will by no means=under no circumstance= on no account绝不 be the reason resulting in the yellow cedar population decline.
因果关系三大表达：
一、十大
一、十大动词词组：前后接名词
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因 n. 果n. 因n. |
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lead to |
be caused by |
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contribute to |
be attributed to |
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result in |
result from |
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give rise to |
stem from |
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be responsible for |
arise from |
Excessive consumption of fast food is responsible for children’s obesity.
人attribute 果 to 因
We attribute children’s obesityto excessive consumption of fast food.
Children’s obesityis attributed toexcessive consumption of fast food.
二、三个连词：后接原因(名词)，连果(句子)
because of/ due to/ owing to
Due to excessive consumption of fast food,children are now suffering from obesity.
三、三个恶果的表达
因is to blame/ is the culprit/ is responsible
When it comes to children’s obesity，excessive consumption of fast foodis to blame/ is the culprit/ is responsible.
