— How nice the fish tastes! Could you tell me who taught you to cook it?
— I learnt it _______watching TV. I learn to cook many dishes_______ TV.
A:by; in
B:by; on
C:in; on
D:in; in
已知tanα=4,计算2sinα+cosαsinα-3cosα=____
47×35= ____ 229×811= ____
家庭电路中,电能表、总开关、保险盒按进户的连接顺序正确的是( )