What is one reason the presence of iridium leads scientists to hypothesize that a meteorite impact caused the mass extinction of dinosaurs.

Kidney stones are tiny crystals of calcium or magnesium that block the narrow sections of the excretory system. which symptoms would a person with kidney stones experience? a. inability to store urine; pain in the bladder b. inability to store urine; pain in the urethra c. reduced urine flow; pain in the bladder d. reduced urine flow; pain in the urethra