如图所示的电路中,两个相同的电流表G1和G2,零点均在刻度盘的中央.当电流从“+”接线柱流入时,指针向左摆;当电流从“-”接线柱流入时,指针向右摆.在电路接通后再断开开关S的瞬间,下述说法中正确的是 ( )
A:G1指针向右摆,G2指针向左摆
B:G1、G2的指针都向右摆
C:G1指针向左摆,G2指针向右摆
D:G1、G2的指针都向左摆
–Which hair band do you like best, madam?–I can't decide now. I really don't know _________.
已知向量a、b的夹角为60°,且a=2,b=1,则向量a与向量a+2b的夹角等于( )