A:should
B:must
C:would
D:shall
如图所示,电源电压保持不变,R为定值电阻,灯泡L标有“6V 3W”字样,当开关S、S1同时闭合时,灯泡L正常发光;当开关S闭合,S1断开时,电流表示数为0.2A(设灯丝电阻不受温度影响).求:
125×8=____ 15×0×30=____ 15+73+27=____ 350÷7=____
102×4=____ 630÷9÷7=____ 66÷6+15=____ 36÷3=____