21.   Such security would be of great value in Hong Kong, which faces a perennial problem of mainland Chinese migrants crossing illegally into the territory.

22.   The lack of actors of color is a perennial problem.

23.   The housing shortage is another perennial problem in New York.

24.   The perennial problem under Dungy has been the offense.

25.   The perennial problem for even the best second bananas is, of course, that they tend to remain one-dimensional.

26.   The picking and choosing from among precedents, a perennial problem in the legal business, also seems particularly egregious here.

27.   This is also the span closer to Oakland, with its perennial problems of self-esteem.

28.   Unfortunately, myths and misconceptions about this perennial problem abound and all too often result in extensive outbreaks that require medical attention.

29.   Perennial problems include the moribund state sector and a growing income gap between wealthy coastal provinces and the lagging hinterland.

30.   Piracy of software and other Western high-tech items is a perennial problem in China, but Microsoft said Wednesday it has signed an anti-piracy agreement with Shenzhen.