Everyone seems to be in favor of progress. But " progress" is a funny word. It doesn't nec

essarily mean that something has become stronger, wiser, or better. It simply means changing it from being one thing to another and sometimes it turns out to be worse than before.

Consider medicine, for instance. No one can deny that medical progress has enriched our lives tremendously. Because of medical advances, we eat better, live easier and are able to take care of ourselves more efficiently. We can cure disease with no more than one injection or a pill. If we have a serious accident, surgeons can put us back together again. If we are born with something defective, they can repair it. They can make us happy, restore our normality, ease our pain, replace worn parts and give us children. They can even bring us back from the dead. These are wonderful achievements, but there is a price we have to pay.

Because medicine has reduced infant mortality and natural death so significantly, the population has been rising steadily, in spite of serious efforts to reduce the rate of population growth. Less than a century ago in the United Stales, infant mortality claimed more than half of the newborn within the first year of life. Medical advances, however, have now reduced that rate to nearly zero. A child born in the United States today has better than a 90% chance of survival. Furthermore, medical advances have ensured that most of these infants will live to be seventy years of age or more, and even that life expectancy increases every year. The result of this progress is an enormous population increase that threatens the quality of life, brought about by progress in the medical profession.

According to this passage, " progress" doesn't always mean that______.

A．something has become stronger and better

B．something has been changed from being one thing to another

C．something has become funny

D．something turns out to be worse than before