若电流i=i1+i2,且i1=10sinwtA,,i2=10sinwtA,则i的有效值为()
A.20A
B.20/2A
C.10A
D.10/2A
参考答案:B
People in China are thankful _____ the Red Cross _____ their donations. [ ]
A. for, with
B. for, to
C. to, for
D. to, with
现在甘肃省会宁城有个会师门,它的命名所依据的重大历史事件是[ ]
A.毛 * * 同朱德所率领的部队会师
B.中央红军和陕北红军会师
C.红二方面军同红四方面军会师
D.红军三大主力会师