题目

Researchers at Oxford University say they have developed a new method that could predict heart attacks years before they happen. They use mathematical algorithms(演算法)to examine CT images of a patient's heart. One report on their study has been published in the medical journal The Lancet.Most heart attacks result from a build-up of fatty tissue inside arteries(动脉)that carry blood from the heart to other areas of the body. Too much buildup can block this flow of blood and cause a heart attack. Currently, doctors use CT scans to learn when a sticky substance called plaque has already bu边长为5的正方形的对角线长是A.自然数B.分数C.无理数D.有理数