题目

由坐标平面内的三点A(1,1),B(3,－1),C(1,－3)构成的△ABC是____________三角形。 答案：等腰直角 — When did the terrible earthquake in Japan happen? — It happened ____ 13:46 ____ the afternoon of March 11th . A. on; in          B. at; on                      C. at; in           D. on; on