61.   Crime is an increasingly serious problem in Russian society.

62.   His ill health poses serious problems for the future.

63.   He had quite serious problems with his chest and wheezed and coughed all the time.

64.   If you have a serious problem with overeating you should get together with others who share this problem.

65.   It is a serious problem and should be treated as such.

66.   Crime is a serious problem in this neighborhood.

67.   Weekend binges are a serious problem at many colleges and universities.

68.   Child abuse has become a serious social problem.

69.   This may be a pointer to a very serious problem.

70.   His delinquent behavior could lead to more serious problems.