61.Identifying the reasons for an emerging phenomenon which involves several complicated factors is far from an easy task.For example, some scientists attribute environmental deterioration to a series of natural factors, while others place the blame solely on inappropriate human behavior.
62.One doesn''t have to look far to realize the direct correlation between smoking and cancer.
63.The explanation for the phenomenon of the rising teenage suicide rate involves many complicated factors.Some attribute the rise to an overemphasis on early success, others point to mounting peer pressure, and still others to confusion over changing social values.
64.The reasons for antisocial behavior are both complicated and varied.I suggest the phenomenon results from inappropriate role models and the lack of well-defined norms of behavior.However, the main reason is quite likely the continuing degeneration of social values.
65.The causes of racial hatred are not readily definable.Sociologists, however, attribute them to the misguided concept of a superior race and an innate mistrust of people of color.Perhaps the main cause is quite simply ignorance.
66.The scourge of HIV/AIDS currently engulfing the world will quite likely be brought under control within the next few years thanks to the untiring efforts of scientists and researchers worldwide.
66.The incidence rate of cancer mainly stems from several factors, including inappropriate diets, poor healthcare practices and the lack of early detection.Continuing medical advances and rising awareness do, however, offer promising hope for the future.
68.Increased urban pollution levels and the mounting death toll from motor vehicles accidents can mainly be attributed to the glut of automobiles appearing on city roads in recent years.Detrimental factors will quite likely outweigh the benefits of rising automobile usage.
69.The rising divorce rate in China can, at least in part, be attributed to spousal incompatibility, disparities in education levels, changing social attitudes and the increasing upward mobility of the younger generation.
70.State-owned enterprises are not only failing because of inefficient management, but also because of their inability to awitch operational modes from the former planned economy to the new market economy.