大全-C-9，大全-C-14问，谢谢

wikeypig

9. Determining the authenticity of purported pre-Columbian artifacts is never easy. Carbon-14 dating of these artifacts is often impossible due to contamination by radioactive palladium (which occurs naturally in the soils of Central and South America). However, historians and anthropologists have evolved two reliable criteria, which, utilized in combination, have proven effective for dating these artifacts. First, because authentic pre-Columbian artifacts characteristically occur in a coarse, granular matrix that is shifted by major earthquakes, they often exhibit the unique scratch patterns known as gridding. In addition, true pre-Columbian artifacts show a darkening in surface color that is caused by centuries of exposure to the minute amounts of magnesium in the soil of the Americas.
The criteria above would be LEAST useful in judging the authenticity of which of the following?
(A) An ax head of black obsidian, unearthed from a kitchen midden
(B) A pottery bowl with a red ocher design, found in the ruins of a temple
(C) A set of gold ear weights, ornamented with jasper pendants
(D) A black feather cape from a king’s burial vault
(E) A multicolored woven sash found near the gravesite of a slave
answer请问为什么？
14. Dr. A: The new influenza vaccine is useless at best and possibly dangerous. I would never use it on a patient.
Dr. B: But three studies published in the Journal of Medical Associates have rated that vaccine as unusually effective.
Dr. A: The studies must have been faulty because the vaccine is worthless.
In which of the following is the reasoning most similar to that of Dr. A?
(A) Three of my patients have been harmed by that vaccine during the past three weeks, so the vaccine is unsafe.
(B) Jerrold Jersey recommends this milk, and I don’t trust Jerrold Jersey, so I won’t buy this milk.
(C) Wingzz tennis balls perform best because they are far more effective than any other tennis balls.
(D) I’m buying Vim Vitamins. Doctors recommend them more often than they recommend any other vitamins, so Vim Vitamins must be good.
(E) Since University of Muldoon graduates score about 20 percent higher than average on the GMAT, Sheila Lee, a University of Muldoon graduate, will score about 20 percent higher than average when she takes the GMAT.
答案：C，B为什么不对？

cranberry

题目1：标准是有刮痕，有曝露在泥土中的变色，而羽毛的披肩是不会有变色或刮痕的


题目2：文章的错误在于毫无理由的否定，而B的错误在于根据消息来源来否定消息的真实，而非全无根据

beechanooi

For C-9: since the feather cape was kept in the king's burial vault, it might not have scrach, nor contact with soil. Key is to understand "vault" - vault also means the place built for the safekeeping of valuables.