题目

-When did the accident happen?         -It happened          9:15           the morning of April  lst, 2015.          A. on; in          B. at; in        C. at; on        D. on; on 答案：C在△ABC中，，．（Ⅰ）求sinA的值；（Ⅱ）设△ABC的面积，求BC的长．