[問題] Prep T2 Q22

[ch655194]

Herbicides allow cereal crops to be grown very efficiently, with virtually no competition from weeds. In Britain, partridge populations have been steadily decreasing since herbicide use became widespread. Some environmentalists claim that these birds, which live in and around cereal crop fields, are being poisoned by the herbicides. However, tests show no more than trace quantities of herbicides in partridges on herbicide-treated land. Therefore, something other than herbicide use must be responsible for the population decrease.

Which of the following, if true about Britain, most seriously weakens the argument?

(A) The elimination of certain weeds from cereal crop fields has reduced the population of the small insects that live on those weeds and that form a major part of partridge chicks' diet.
(B) Since partridges are valued as game birds, records of their population are more carefully kept than those for many other birds.
(C) Some of the weeds that are eliminated from cereal crop fields by herbicides are much smaller than the crop plants themselves and would have no negative effect on crop yield if they were allowed to grow.
(D) Birds other than partridges that live in or around cereal crop fields have also been suffering population declines.
(E) The toxins contained in herbicides typically used on cereal crops can be readily identified in the tissues of animals that have ingested them.

這題答案是A選項，我不懂得是，他的問題是most serious weaken the argument, 而題幹最後一行的結語是Therefore, something other than herbicide use must be responsible for the population decrease.那答案A不就正好support 他的argument了嗎?

這題我A D抉擇了好久,最後選D....

[vantreal]

(D) Birds other than partridges that live in or around cereal crop fields have also been suffering population declines.

這個是很標準的擴大議題範圍.
其他鳥類減少的話, 搞不好是被獵人獵殺的, 天氣冷凍死的 (有太多種可能性了).

題目說: something other than herbicide use must be responsible for the population decrease.
weaken: 否決議題conclusion --> herbicide use MUST BE responsible for the population decrease.

(A) The elimination of certain weeds from cereal crop fields has reduced the population of the small insects that live on those weeds and that form a major part of partridge chicks' diet.
雜草被除掉以後, 減少了原本在雜草生存上的蟲蟲, 而且這些蟲蟲是松雞的主食.
--> 表示所以表示被herbicide影響到的雜草讓蟲蟲變少, 松雞餓死, 自然松雞的數量就減少囉~~

[pimi]

這題真的很容易誤導要weaken"一定有其他除了herbicide以外的東西導致數量下降", 就是要找出為何herbicide無法在partridge體內測得~

所以A選項也讓人誤解是support argument, 是insect下降而不是herbicide use 導致partridge數量下降~

其實仔細想想, 雖然insect的下降, 是導致partridge數量下降的主因, 但是若不是herbicide use, insect也不會下降, 所以A選項解釋了為何partridge雖然因為herbicide use而數量下降, 但是在體內卻測不得毒素的原因, 所以也weaken了結論的something other than herbicide use must be responsible for the population decrease.