71.   But as this region became the main Soviet source of cotton, a maze of irrigation canals was built.

72.   But Europe is not the main source of trouble for American steel mills.

73.   But movies were the main source material for Boutsikaris, though he also attempted to glean Allen from his rare real-life appearances as well.

74.   But it is not the main source of delay now.

75.   But Soss said that many corporations no longer regard higher revenue as the main source of profit and see cost-cutting as a major profit center as well.

76.   But the main source of tension between the United States and Egypt still has far more to do with Israel than with Boutros-Ghali.

77.   But the main sources remain overwhelmingly French.

78.   But the main source of noise cancellation for the race car system is a variation on conventional arrays.

79.   But their main source of pride is the crackhouses they say they have shut down and the parks, streets and even supermarkets they say they have made safe.

80.   But there has been little discussion so far of water rights, for instance, given that two main sources of the Jordan River begin in the Golan.