A:保护
B:排泄
C:调节体温
D:产生感觉
设△ABC的内角A、B、C所对的边分别为a,b,c,且满足cosA2=255,AB→·AC→=3
(1)求△ABC的面积;
(2)求a的最小值.
How often do you have a(n)____ ____ ?