Critical Reasoning

After the national speed limit of 55 miles per hour was imposed in 1974, the number of deaths per mile driven on a highway fell abruptly as a result. Since then, however, the average speed of vehicles on highways has risen, but the number of deaths per mile driven on a highway has continued to call.
Which of the following conclusions can be properly drawn from the statements above?
A. The speed limit alone is probably not responsible for the continued reduction in highway deaths in the years 1974.
B. People have been driving less since 1974.
C. Driver education courses have been more effective since 1974 in teaching drivers to drive safely.
D. In recent years highway patrols jave been less effective in catching drivers who speed.
E. The change in the speed limit cannot be responsible for the abrupt decline in highway deaths in 1974.

A and E both seem like good answers...they kind of sound the same!

Bats emit sounds and generally use the echoes of these sounds highly efficently to detect, locate and catch their preys. However, it is claimed that the characteristic efficiency of this process is reduced by moths able to hear the sounds emitted by insect-eating bats.
Which of the following statements if true, best supports the claim above?
A. Those moths cannot hear the sounds emitted by insect-eating bats live longer on the average than those that can hear such sounds when both kinds of moth are in an environment continuously free of such bats.

B. Those moths that cannot hear the sounds emitted by insect-eating bats are among the species of insects that are most liekly to be caught by such bats.

C. When a moth changes its speed or direction of flight, there is a change in the sound pattern generated by the moth's wing movements.

D. Moth species that can hear the sounds emitted by insect-eating bats are less-likely to be caught by such bats than are moths species that cannot hear these sounds.

E. Moths that are capable of hearing the sounds emitted by insect-eating bats differ in their abilities to use evasive action to escape capture by such bats.

B vs. D???

Question #1
You are right, but the main difference here is that E) says “cannot” (100% sure) while A) says “is probably” . We don’t know for sure therefore, A) is more appropriate. GMAT is always very cautions about drawing conclusions that are either out of scope or are too extreme. I belive this is a good trick to learn

Question#2

There are very, very similar. It took me a while to figure out. I would go with D on the grounds that it specifically talks about moths. B) compares moths to other species of insects and perhaps this is a little out of scope.
Tough one!

Sentence 1)

The correct answer should be able to explain the anomaly. Earlier, after the imposition of the speed limit, the number of deaths per mile, fell abruptly. It could have been attributed to the new speed limits. However, the second part highlights the fact that even after the speed limits were withdrawn the number of deaths continued to fall.

A sounds like the right answer to me, since it explains that speed limits alone might not be responsible for this reduction. E uses the word "cannot" which is too extreme.

Whats the OA?

For the second one, I would go for D...

Both are deceptively similar though. Please share the OA

the OAs are A and D

IMO:

A for first one.

D for second one.

Thanks.