On its website, petrol company Shell said prices can vary from region to region due to "factors such as distance from the refinery or distribution terminal to the petrol station and the number of customers in the region".

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Revenue hit a record high even though gold-mining output was down from the year-ago quarter due to factors such as mine sequencing and lower ore grades in certain mines.

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However the report does acknowledge the improvement in core performance from the banks, and says it is due to two main factors.

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The supply of labor is shifting downward due to demographic factors, as well as changes in behavior resulting from a rising premium for education.

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With the new 40, 000-wafers-per-month Israeli mega-factory due to come on line next year, these factors point to continued margin expansion from already sharply rising levels.

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It has never been clear, for instance, exactly which cases of heart disease result from greater susceptibility as the body gets old and which are largely due to environmental factors.

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Abrams, senior fellow for middle eastern studies at the Council on Foreign Relations, said President Obama has a better chance of effectively employing sanctions against Iran than President Bush did due to two factors: the drop in cost of oil and the possibility of increased cooperation from Russia and China.

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