Reading Comprehension Success in 20 Minutes a Day, 3rd Edition

Practice in Identifying Topic
Sentences
Remember that a topic sentence is a clear statement of
the main idea of a passage; it must be general enough
to encompass all the ideas in that passage, and it usu-
ally makes an assertion about the subject of that pas-
sage. Knowing all that, you can answer the following
question even without reading a passage.
Practice 1
2.
Which of the following sentences is general
enough to be a topic sentence?
a.
The new health club has a great kickboxing
class.
b.
Many different classes are offered by the
health club.
c.
Pilates is a popular class at the health club.
d.
The yoga class is offered on Saturday
mornings.
The answer is 
b
, “Many different classes are
offered by the health club.” Answers 
a
,
c
, and 
d
are all
specific examples of what is said in 
b
, so they are not
general enough to be topic sentences.
Practice 2
Now look at the following paragraph. Underline the
sentence that expresses the main idea, and notice how
the other sentences work to support that main idea.
Erik always played cops and robbers when he was a
boy; now, he’s a police officer. Suzanne always played
school as a little girl; today, she is a high-school
math teacher. Kara always played store; today, she
owns a chain of retail clothing shops. Long before
they are faced with the question, “What do you want
to be when you grow up?” some lucky people know
exactly what they want to do with their lives.
Which sentence did you underline? You should
have underlined the 
last
sentence: “Long before they are
faced with that question ‘What do you want to be when
you grow up?’ some lucky people know exactly what
they want to do with their lives.” This sentence is a
good topic sentence; it expresses the idea that holds
together the whole paragraph. The first three
sentences—about Erik, Suzanne, and Kara—are 
specific
examples
of these lucky people. Notice that the topic
sentence is found at the 
end
of the paragraph.