An air traveler in Beijing

Answer choices

1. A

   Bad Validity Match2% picked this

   A doctor cannot prescribe porozine for a patient without first prescribing anthroxine for that patient. Unfortunately, anthroxine makes most patients who take it feel

   The original is valid; this argument is invalid. The original chains necessary conditions: Lhasa needs Chengdu, Chengdu needs Xian, so Lhasa needs Xian. (A) starts with porozine requiring anthroxine, then gives an effect of anthroxine (it makes most patients drowsy or nervous), then concludes a particular patient who took porozine "likely felt nervous." That's a leap from "most patients" and "drowsy or nervous" to a specific outcome, which the original argument never makes. Different structure and invalid.

   2%
2. B

   Correct90% picked this

   An ice-sculpture artist cannot reach the yellow level of achievement without first achieving the green level. The green level is impossible to achieve unless

   Why this is right

   This matches the original's structure perfectly. Yellow requires green (cannot reach yellow without first achieving green). Green requires white (green is impossible without white). Therefore, yellow requires white. Same three-step chain of necessary conditions, same valid transitive structure.

   Skill tested: Parallel · how this choice captures the argument's function is the move to repeat next time.

   90%
3. C

   Bad Conclusion Match4% picked this

   One cannot properly identify a mushroom without first examining its spores. A powerful microscope can be used to examine the spores of a mushroom.

   The first premise gives a necessary condition (examining spores is necessary for proper identification). The second premise says a powerful microscope can be used (sufficient, not necessary). The conclusion claims a powerful microscope is necessary, but no premise established that — only that it's one option. The original argument's conclusion follows; this one doesn't. Different structure.

   4%
4. D

   Bad Conclusion Match1% picked this

   It is impossible to be fluent in a language without knowing its grammatical rules. A person who knows the grammatical rules of a language

   The first premise is a necessary condition (knowing rules is needed for fluency). The second premise lists two ways to learn the rules. The conclusion claims there are "two major ways to become fluent" — but learning the rules is necessary for fluency, not sufficient. Even after learning the rules, you might not become fluent. The original argument's conclusion was a necessary-condition chain; (D) shifts to listing pathways. Different structure.

   1%
5. E

   Bad Validity Match2% picked this

   In the City Ballet Company any dancer who has danced in Giselle has also danced in Sleeping Beauty, and some dancers who have danced

   This argument has an "all" premise and a "some" premise, leading to a "some" conclusion. The original is a chain of necessary conditions and is deductively valid; (E) has different premise types and is also valid only in a different way. Crucially, the original argument doesn't involve overlap of subgroups — it's a sequential dependency. Structurally, (E) doesn't match.

   2%