81.   The rarity of the disease makes it difficult to diagnose.

82.   These changes will make life difficult for everyone involved.

83.   The years had snowed his hair to a silvery white, making it difficult at first to recognize her old high school crush.

84.   Accusations and reproaches from both parties made it difficult to pursue discussions.

85.   Heavy fog made it difficult to see the road.

86.   Patchy fog made driving difficult.

87.   Now governments and businesses realise bad air and water pollution affect everyone, making it difficult for cities to survive and for businesses to make a profit.

88.   This information is increasingly becoming of local nature, C C T and L M S make it difficult for our national research department to deal with local issues.

89.   Thus, the absence of a common framework for evaluating risks can make it difficult to arrive at consensus decisions.

90.   This is made particularly difficult because no specific psychological mechanism is necessarily proposed to explain the relationships underlying the effect.