English Skills with Readings 8th Edition by John Langan

Exercise 61

Each group of sentences below could be written as a short paragraph. Circle the letter of the topic sentence in each case. To find the topic sentence, ask yourself, "Which is a general statement supported by the specific details in the other three statements "
Begin by trying the example item below. First circle the letter of the sentence you think expresses the main idea. Then read the explanation.
EXAMPLE
a. If you stop carrying matches or a lighter, you can cut down on impulse smoking.
b. If you sit in no-smoking areas, you will smoke less.
c You can behave in ways that will help you smoke less.
d. By keeping a record of when and where you smoke, you can identify the most tempting situations and then avoid them.
EXPLANATION Sentence a explains one way to smoke less. Sentences b and d also provide specific ways to smoke less. In sentence c, however, no one specific way is explained. The words ways that will help you smoke less refer only generally to such methods. Therefore, sentence c is the topic sentence; it expresses the author's main idea. The other sentences support that idea by providing examples.
a. The last time I ate at the diner, I got food poisoning and was sick for two days.
b. The city inspector found roaches and mice in the diner's kitchen.
c. Our town diner is a health hazard and ought to be closed down.
d. The toilets in the diner often back up, and the sinks have only a trickle of water.