KÈM LÝ DO >< A new study shows that women can reduce their chances of developing heart disease by jogging for about three hours every week. The researchers at Harvard University Medical in Boston have just reported the results of the study on the New England Journal of Medicine. The study is the first to show the____(23)_____ of jogging in the developing of heart disease in women. Only _____(24)_______ earlier studies have examined the effects of jogging on the heart, _____(25)______ nearly all have been done on men. The new study involves more than 72,000 women between the ages of forty and sixty-five during a period of eight years. The researchers have found that women ____(26)_____ jog at least three hours a week have a thirty to forty percent lower chance of suffering a heart attack than those who do not. 23. A. effective B. effectively C. effectiveness D. effect 24. A. little B. a little C. few D. a few 25. A. and B. but C. or D. so 26. A. which B. whom C. who D. whose