Finding the Main Idea
Exercise 1


Write the topic and the number of the topic sentence containing the main idea for each of the following paragraphs. The topic sentence could be located at any place within the paragraph.


1.  

1Although we have scientific evidence that women should not smoke when they are pregnant, many future mothers ignore this danger. 2Not only are these mothers endangering the physical health of their babies, but they also could be contributing to even more problems in the future. 3In addition to the known problems, recent studies have linked mothers' smoking during pregnancy with sons who go on to become criminals. 4Researchers in Finland followed over 5,000 males and their mothers from the time the mothers were six months pregnant until the young men were 28 years old. 5Compared to sons whose mothers did not smoke during pregnancy, those young men whose birth mothers did smoke were more than twice as likely to commit criminal acts. 6The researchers theorized that smoking during pregnancy may alter the chemical balance in the baby's brain. 7This recent information, added to the body of evidence available for years, should be a warning to pregnant women to give up smoking.



2.  

1In our right-handed society, why are some people left-handed? 2Although the reasons for hand preference are not fully explained, studies have provided us with some general information regarding left-handedness. 3For instance, more males than females have this characteristic, although the difference is only slight. 4In addition, it seems to appear within families where a father and son will share this preference. 5Another connection shows some left-handed people also have dyslexia, a type of reading disability. 6Although being left-handed does not cause dyslexia, it could somehow be connected with difficulty in awareness between right and left. 7Child development specialists found hand preference usually develops at about age seven, but may switch back and forth up until the age of nine or ten. 8It should be noted that despite left-handed people experiencing some inconvenience in our right-handed world, there is no evidence to support retraining children to use their right hand.



3.  

1We escaped from the bitter cold of the Northeast to visit the balmy island resort and enjoy the sun and crystal blue water. 2It was a perfect time to watch the far-off sails of the fishing boats, run our fingers through the fine, powdery sand on our private beach, listen to soothing music, or simply read a favorite novel for hours on end. 3It was paradise! 4We were determined to recapture this unforgettable experience every year. 5And we did, until the spring of 2001 when the balmy island resort came under attack by visiting hoards of wild spring-break revelers. 6No longer did we have our beach to ourselves; we now could easily hit the volleyball from our beach chairs, share in the joys of blaring rock music, and fight for a glimpse of the water through the throngs of frolicking folks. 7It is amazing how a paradise can change.



4.  

1Sometimes it is a money issue: too many credit cards to pay off, lack of scholarships or other college aid. 2Sometimes it is a child care problem: the cost of care, the lack of reliable centers, or transportation to get the children there. 3Sometimes it is the demands of the hours spent at work which leave little time for class. 4All of these reasons and more often stand in the way of women returning to college, yet many women are finding ways to achieve their goal of a higher education. 5Some of the monetary concerns are being addressed by financial aid counselors who help these women uncover funding sources. 6In addition, many of the women are enrolling in community colleges where the tuition is generally more affordable. 7Colleges are also helping by recognizing the need for on-site daycare centers and by using students within their education departments to help at the centers. 8Finally, employers are investing in having working women return to the classroom by providing time to attend class during the work day or by supplementing the cost of taking courses. 9With these resources, perhaps even more women will be able to return to school.



5.  

1For many individuals suffering from a reading disability, the use of colored plastic overlays on books can produce dramatic improvement. 2Studies conducted at the University of New Orleans found about 80 percent of individuals with specific visual defects responded positively to this simple procedure. 3The use of colored overlays, particularly blue and gray, seem to reduce the contrast between the print and background, thus reducing distortions of the written material. 4The study cautioned, however, that there are individual differences in the effects of using different colors, so each reader should be carefully tested.

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