Question

read the passage. there are several questions about this passage.
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.
3
lets move on from licking cats to licking static cling. this too has to do
with electron transfer. the tendency for such transfer is known as the
triboelectric effect and the triboelectric series is a list of substances in order
of their ability to lose or gain electrons. substances at the top of the list tend
to lose electrons readily, at the bottom, they are more likely to gain
electrons.
4
the triboelectric effect was first described around 600 b.c., by the greek
mathematician thales. of course, there was no reference to electrons, which
were not discovered until 2,500 years later by j.j. thomson. thales noted
that light objects such as feathers were attracted to a chunk of amber that
he had been polishing with a piece of fur. as we now understand, the
rubbing transfers electrons from the fur to the amber, giving the latter a
negative charge. when the negatively charged amber is brought close to a
feather, it repels electrons from the feather’s surface, making the surface
positive. the attraction between the positive areas of the feather and the
negative areas of the amber is an example of static cling.
5
a similar effect occurs when a plastic comb is run through hair. since
hair is above plastic in the triboelectric series, electrons are transferred
from the hair to the comb, which can then pick up light objects just like the
charged amber. since the hair fibers have lost electrons, they become...
this sentence is from the passage.
\lets move on from licking cats to licking static cling.\ (paragraph 3)
what role does this sentence play in the development of the ideas in the passage?

1. it serves as a conclusion to the discussion of

the effect of humidity and moisture on static
electricity.

1. it suggests that cats methods for avoiding

static electricity were the inspiration for
anti - cling fabric softeners.

1. it introduces an aspect of static electricity that

is fundamentally different from the aspects
described in the opening paragraphs about
cats.

1. it uses wordplay to signal a transition from the

specific situation of cats to a general
explanation of the principles involved in static
electricity.

Explanation:

• Option 1: The sentence is not a conclusion for the humidity - moisture - static electricity discussion; it's a transition, so 1 is wrong.
• Option 2: There's no info in the passage linking cat methods to anti - cling fabric softeners, so 2 is incorrect.
• Option 3: Static cling (introduced here) and the cat - related static electricity both involve electron transfer, so they aren't fundamentally different, making 3 wrong.
• Option 4: The sentence uses "licking cats" (specific situation) and "licking static cling" (wordplay for transition) to move from the cat example to explaining static electricity principles generally. This matches the sentence's role.

Answer:

1. It uses wordplay to signal a transition from the specific situation of cats to a general explanation of the principles involved in static electricity.