rakeshd347 wrote: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.
Herbs. destroy certain weeds and which in turn reduces the primary source of nutrition of the small insects and thus they die. Eventually the bird population also decreases as the young ones dont have enough small insects to eat. Strong contender

B. Since partridges are valued as game birds, records of their population are more carefully kept than those for many other birds.
Out of scope: Does not talk about Herbs.

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.
Presents no correlation between the birds and herbs.

D. Birds other than partridges that live in or around cereal crop fields have also been suffering population declines.
Provides no reason for the decline.

E. The toxins contained in herbicides typically used on cereal crops can be readily identified in the tissues of animals that have ingested them.
This provides additional premise that Herb. traces can indeed be detected.

rakeshd347 wrote: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.

OA is A