GWD3-Q38

[schung0529]

Q38:
Kate: The recent decline in numbers of the Tennessee warbler, a North American songbird that migrates each fall to coffee plantations in South America, is due to the elimination of the dense tree cover that formerly was a feature of most South American coffee plantations.

Scott: The population of the spruce budworm, the warbler’s favorite prey in North America, has been dropping. This is a more likely explanation of the warbler’s decline.

Which of the following, if true, most seriously calls Scott’s hypothesis into question?

A. The numbers of the Baltimore oriole, a songbird that dose not eat budworms but is as dependent on South American coffee plantations as is the Tennessee warbler, are declining.
B. The spruce-budworm population has dropped because of a disease that can infect budworms but not Tennessee warblers.
C. The drop in the population of the spruce budworm is expected to be only temporary.
D. Many Tennessee warbler have begun migrating in the fall to places other than traditional coffee plantations.
E. Although many North American songbirds have declined in numbers, no other species has experienced as great a decline as has the Tennessee warbler.


我選C ~但答案為什麼是A?

[維尼]

因為 A 比 C 更好: 不吃蟲的鳥一樣減少

[吳]

kate:T鳥近來減少,是樹的關係
scott:是蟲的關係

(a)B鳥減少,是樹的關係,跟蟲沒關係--->他因 (不過好像有點牽強.....)
(c) 蟲暫時性減少:反而support scott,呼應T鳥近來減少

[winihsi]

Q38:
Kate: The recent decline in numbers of the Tennessee warbler, a North American songbird that migrates each fall to coffee plantations in South America, is due to the elimination of the dense tree cover that formerly was a feature of most South American coffee plantations.

Scott: The population of the spruce budworm, the warbler’s favorite prey in North America, has been dropping. This is a more likely explanation of the warbler’s decline.

Which of the following, if true, most seriously calls Scott’s hypothesis into question?

A. The numbers of the Baltimore oriole, a songbird that dose not eat budworms but is as dependent on South American coffee plantations as is the Tennessee warbler, are declining.
B. The spruce-budworm population has dropped because of a disease that can infect budworms but not Tennessee warblers.
C. The drop in the population of the spruce budworm is expected to be only temporary.
D. Many Tennessee warbler have begun migrating in the fall to places other than traditional coffee plantations.
E. Although many North American songbirds have declined in numbers, no other species has experienced as great a decline as has the Tennessee warbler.


我選C ~但答案為什麼是A?

Kate說:Tennessee warbler數量的減少是因為咖啡農地樹的被砍
Scott說:不是因為咖啡農地上的樹數量減少的關係,而是因為warbler吃的蟲的數量減少的關係

那如果要否決掉scott的說法,就要證明warbler數量減少確實是因為咖啡農地上樹的減少而影響
A:B鳥(和warblar一樣是songbird的一種,但是他不吃w吃的那一種蟲budworm)和w鳥一樣需要靠咖啡農地上的樹,而b鳥的數量也減少

-->由此可知,主要讓w鳥數量減少的原因是因為咖啡農地上的樹被砍的原因