A:to seeing
B:to see
C:for seeing
D:and see
下列说法中,不正确的是( )
16100 =____
如图所示电路,当开关S闭合,甲乙两表均为电压表,两表读数之比U甲:U乙=3:1,则R1:R2=____ ;当开关S断开,甲乙两表均为电流表,两表读数之比I甲:I乙=____ .