You often clean the kitchen by _______.
The Huanghe River isn't so ____ (long) as the Changjiang River.
在△ABC中,角A,B,C所对的边分别为a,b,c,已知2a+bc=cosA+CcosC
(1)求角C的大小,
(2)若c=2,求使△ABC面积最大时a,b的值.