A. B. C. D. E.
在△ABC中,内角A,B,C所对的边分别是a,b,c,已知△ABC的面积S=12a2-b-c2.
(Ⅰ)求sinA与cosA的值;
(Ⅱ)设λ=ba,若tanC=2,求λ的值.
An engine is a machine _______ can make a car move.
如图,所示的电路中,电源电压保持不变,开关S闭合后,滑片P向右滑动时( )
I am good at playing basketball,and my brother is good at it.