Question

read the passage. there are several questions about this passage.

from cats, calamities, and static cling

1
have you ever wondered why, on some days, cats lick themselves more vigorously than on others? i suspect not. but their licking rate is indeed variable. and it just might have to do with the animals fear of getting an electric shock. unfortunately for felines, cat fur loses electrons very readily, and therein lies a problem. anytime a cat rubs up against something—and they do a lot of rubbing up—electrons are transferred from the cat to the object, leaving the cat positively charged. when the animal now comes close to items that are good electrical conductors and therefore readily give up electrons, it is subjected to an electrifying experience. a spark, which is nothing more than a stream of electrons, can jump from the item to the cat. and then the cat jumps. unless it has engaged in some preventative licking.

2
the buildup of static electricity is less likely when there is moisture in the air, due to a couple of factors. water in the air makes the air more conductive, making for an easier dissipation of any charge that has built up. furthermore, water molecules, being polar, also bind to the charged material. \polar\ means that within the molecule electrons are distributed in a fashion so as to make the oxygen atom slightly negative and the hydrogen atoms slightly positive. cat fur being positively charged attracts the negative end of water molecules, which means the positive charge is partially neutralized, making the fur less attractive to any source of electrons. the risk of a spark is diminished. when humidity is low, the cat has to use saliva to moisten its fur to prevent being shocked. since low humidity is usually associated with good weather, a cat licking itself with increased enthusiasm is a sign that rain is not likely. if you prefer not to use your cat as a barometer, a little spray with water will do the trick. but you may lose some affection.

the idea that moisture is an effective remedy for static buildup is first introduced in paragraph 2.

how does paragraph 6 help readers better understand this idea?

1. it names a wide variety of chemical substances that are superior to water for eliminating static.

1. it describes the structure of strands of human hair when they are dry and how the structure changes when hair gets wet.

1. it offers an explanation of how the molecular structure of antistatic agents works with water to neutralize electric charge.

1. it identifies the role that friction plays in preventing human hair from becoming positively charged and in decreasing static cling in fabrics.

Explanation:

To solve this, we analyze each option:

• Option 1: The passage's idea is about moisture (water) as a remedy. Stating other substances are superior contradicts this, so 1 is wrong.
• Option 2: Paragraph 6 (not fully shown, but contextually) likely uses human hair as an example. Dry human hair structure and its change when wet would relate to how moisture (like saliva for cats, water for hair) affects static. This helps explain the moisture - static idea by analogy (human hair similar to cat fur in static issues).
• Option 3: The idea in paragraph 2 is about moisture (water) as a remedy, not antistatic agents' molecular structure. So 3 is off - topic.
• Option 4: The main idea is about moisture, not friction's role in preventing charge. So 4 is incorrect.

Answer:

1. It describes the structure of strands of human hair when they are dry and how the structure changes when hair gets wet.