1. Which word best completes the sentence?
A. malleable Correct
B. obscure
C. ominous
D. vigorous
Explanation
Malleable' means capable of being shaped or molded, which fits perfectly with the context of plastics being formed into various shapes through processes like casting or extrusion. The other options—obscure (unclear), ominous (threatening), and vigorous (energetic)—do not align with the described properties of plastics.
2. Tchaikovsky's Nutcracker leaves an impression on audiences: children especially remember the dazzling costumes and stirring music. Which word best completes the sentence?
A. amorphous
B. indelible Correct
C. ineffable
D. inscrutable
Explanation
Indelible' means unforgettable or unable to be erased, which fits the idea of the Nutcracker leaving a lasting impression, especially on children who remember its costumes and music. Amorphous (shapeless), ineffable (too great to describe), and inscrutable (difficult to understand) do not convey the sense of a lasting, memorable impact.
3. The main idea of the passage is that some types of poison frogs:
A. have developed the capacity to protect themselves from the poison they carry in their skin Correct
B. could eventually produce a natural pain relief option for people who suffer from headaches
C. combine chemicals from their food to create a toxic substance that keeps them safe from predators
D. can be grouped based on the changes they've made to their nicotinic acetylcholine receptors
Explanation
The passage explains that poison frogs carry a potent toxin (epibatidine) in their skin, which is deadly to rodents but harmless to the frogs themselves because of changes to a receptor in their bodies. This highlights their evolutionary adaptation to resist self-toxicity, making Option A the main idea.
4. Which choice best replaces the underlined portion of sentence 1 (reproduced below)? When selecting her ingredients, a chef has a seemingly small-but nonetheless consequential choice-she can patronize a conventional grocery store, or she can turn to a nearby farm.
A. small but nonetheless consequential choice,
B. small but nonetheless consequential choice: Correct
C. small-but nonetheless consequential choice;
D. small but nonetheless, consequential choice,
Explanation
The sentence sets up a complete independent clause that introduces a list of two options: going to a grocery store or a farm. The most appropriate punctuation before listing or explaining multiple items following an independent clause is a colon (:).
5. Which is the best version of the underlined portion of sentence 2 (reproduced below)? Supposing a store may provide benefits such as a broad range of options, a local farm can offer major advantages of its own.
A. (as it is now)
B. When a store supposes it
C. Although a store Correct
D. A store though
Explanation
Choice C ('Although a store') is clear and grammatically correct. It introduces a concession (that a store has benefits), which contrasts well with the second clause about the advantages of a local farm.