Critical Reasoning

Hi,
I got the following questions wrong in the CR1000 LSAT Test. Can anyone explain correct answers?

Section LSAT - Test 2 - Section 2:

5. A gas tax of one cent per gallon would raise one billion dollars per year at current consumption rates. Since a tax of fifty cents per gallon would therefore raise fifty billion dollars per year, it seems a perfect way to deal with the federal budget deficit. This tax would have the additional advantage that the resulting drop in the demand for gasoline would be ecologically sound and would keep our country from being too dependent on foreign oil producers.
Which one of the following most clearly identifies an error in the author’s reasoning?
(A) The author cites irrelevant data.
(B) The author relies on incorrect current consumption figures.
(C) The author makes incompatible assumptions.
(D) The author mistakes an effect for a cause.
(E) The author appeals to conscience rather than reason. (Answer: C)

7. There is no reason why the work of scientists has to be officially confirmed before being published. There is a system in place for the confirmation or disconfirmation of scientific finding, namely, the replication of results by other scientists. Poor scientific work on the part of any one scientist, which can include anything from careless reporting practices to fraud, is not harmful. It will be exposed and rendered harmless when other scientists conduct the experiments and obtain disconfirmatory results.
Which one of the following, if true, would weaken the argument?
(A) Scientific experiments can go unchallenged for many years before they are replicated.
(B) Most scientists work in universities, where their work is submitted to peer review before publication.
(C) Most scientists are under pressure to make their work accessible to the scrutiny of replication.
(D) In scientific experiments, careless reporting is more common than fraud.
(E) Most scientists work as part of a team rather than alone. (Answer : A)


11. “If the forest continues to disappear at its present pace, the koala will approach extinction,” said the biologist.
“So all that is needed to save the koala is to stop deforestation,” said the politician.
Which one of the following statements is consistent with the biologist’s claim but not with the politician’s claim?
(A) Deforestation continues and the koala becomes extinct.
(B) Deforestation is stopped and the koala becomes extinct.
(C) Reforestation begins and the koala survives.
(D) Deforestation is slowed and the koala survives.
(E) Deforestation is slowed and the koala approaches extinction. (Answer : B)



12. People have long been fascinated by the paranormal. Over the years, numerous researchers have investigated telepathy only to find that conclusive evidence for its existence has persistently evaded them. Despite this, there are still those who believe that there must be “something in it” since some research seems to support the view that telepathy exist. However, it can often be shown that other explanations that do comply with known laws can be given. Therefore, it is premature to conclude that telepathy is an alternative means of communication.
In the passage, the author
(A) supports the conclusion by pointing to the inadequacy of evidence for the opposite view
(B) supports the conclusion by describing particular experiments
(C) supports the conclusion by overgeneralizing from a specific piece of evidence
(D) draws a conclusion that is not supported by the premises
(E) rephrases the conclusion without offering any support for it (Answer : A)



Thanks,
Srikanth