1.Too much work and too little rest may lead to loss of health.

       2.If you try to learn too many things at a time，you may get confused.

       3.We have made numerous attempts to solve the problems，but so far our efforts have been unsuccessful.

       4.State financial support given in the form of scholarships has stimulated the students to greater efforts.

       5.The pressures of modern urban life have led to increased occurrences of alcoholism and drug abuse，mental illness，suicide，and divorce in our society.

       6.We note with satisfaction that all these activities have helped to promote mutual understanding and friendship between two peoples.

       7.The population is leveling off(处于平衡状态) in the area as a result of family planning.