it is enough to choose one of them so that windows would open a given extension with it. when i took out the sheet it feels very smooth so right away i thought how is this going to grip. i suppose mathematicians get trained to stop thinking about individual problems and instead look to classes of problems. the lemon zest, salt, and pepper that are in the recipe are a decent substitute for the sumac. it can come back to bite you so easily - now or at any time in the future. 