21.   All these factors can contribute to sick-building syndrome.

22.   All these factors should contribute to a decline in fertility.

23.   All these factors contributed to a climate in which Fujimura was allowed to get away with his repetition of academic fraud.

24.   Bricker and UW psychology Professor Irwin Sarason wanted to figure out what factors contributed most to air travel stress in general, not just assaultive behavior.

25.   Both factors clearly contributed to the resonant realism of the piece.

26.   But an official acknowledged that other factors contributed.

27.   But he cautioned that the analysis does not rule out the possibility that other, unknown factors are contributing to the learning gap.

28.   But several factors may have contributed to the rise in violent incidents.

29.   But weather experts say that other factors have contributed to the growing fascination.

30.   Certainly, other factors have contributed to the softness in compensation growth in the past few years.