GMATPre几题请教，多谢！

刚刚开始准备二战，下个月初考，现在在做分项练习，做逻辑的时候总是在二选一中徘徊，还望牛人提点

第一套24.

Tiger beetles are such fast runners
that they can capture virtually any nonflying insect.  However, when running toward an insect, the
beetles intermittently stop, and then, a moment later, resume their
attack.  Perhaps they cannot maintain
their pace and must pause for a moment's rest; but an alternative hypothesis is
that while running tiger beetles are unable to process the resulting rapidly
changing visual information, and so quickly go blind and stop.

Which of the following, if
discovered in experiments using artificially moved prey insects, would support
one of the two hypotheses and undermine the other?

(A) When a prey insect is moved
directly toward a beetle that has been chasing it, the beetle immediately turns
and runs away without its usual intermittent stopping.

(B) In pursuing a moving insect,
the beetles usually respond immediately to changes in the insect's direction,
and pause equally frequently whether the chase is up or down an incline.

(C) The beetles maintain a fixed
time interval between pauses, although when an insect that had been stationary
begins to flee, the beetle increases its speed after its next pause.

(D) If, when a beetle pauses, it
has not gained on the insect it is pursuing, the beetle generally ends its
pursuit.

(E) When an obstacle is suddenly
introduced just in front of running beetles, the beetles sometimes stop
immediately, but they never respond by running around the barrier.

Key：C，如何在B和C间选择？

第一套：46

Archaeologists in Michigan have
excavated a Native American camp near Dumaw Creek.  Radiocarbon dating of animal bones found at
the site indicates that the camp dates from some time between 1605 and 1755.  However, the camp probably dates to no later
than 1630, since no European trade goods were found at the site, and European
traders were active in the region from the 1620's onward.

Which of the following, if true,
most strengthens the argument?

(A) Due to trade among Native
Americans, some European trade goods would have reached the area before the
European traders themselves did.

(B) At all camps in the region that
have been reliably dated to the late 1620's, remains of European trade goods
have been found.

(C) The first European trade goods
to reach the area would have been considered especially valuable and preserved
as much as possible from loss or destruction.

(D) The first European traders in
the area followed soon after the first European explorers.

(E) The site is that of a temporary
camp that would have been used seasonally for a few years and then abandoned.

Key：B，如何在A和B间选择

第一套65

Sales of telephones have increased
dramatically over the last year. In order to take advantage of this increase,
Mammoth Industries plans to expand production of its own model of telephone,
while continuing its already very extensive advertising of this product.

Which of the following, if true,
provides most support for the view that Mammoth Industries cannot increase its
sales of telephones by adopting the plan outlined above?

(A) Although it sells all of the
telephones that it produces, Mammoth Industries' share of all telephone sales
has declined over the last year.

(B) Mammoth Industries' average
inventory of telephones awaiting shipment to retailers has declined slightly
over the last year.

(C) Advertising has made the brand
name of Mammoth Industries' telephones widely known, but few consumers know
that Mammoth Industries owns this brand.

(D) Mammoth Industries' telephone
is one of three brands of telephone that have together accounted for the bulk
of the last year's increase in sales.

(E) Despite a slight decline in the
retail price, sales of Mammoth Industries' telephones have fallen in the last
year.

Key：E 如何在A.E中选择？

多谢！！感激不尽！！