在如图所示的电路中,电源电压恒定,L1、L2均标有“6V 6W”字样(设灯丝的电阻不变)。当S1、S2闭合时,灯L1正常发光;则S1闭合,S2断开时,两盏等的总功率是()
A:12W
B:6W
C:3W
D:2W
用显微镜观察“生物”二字,显微镜下看到的图形应该是下列哪种情况( )
Girls usually like _______ with friends while boys like playing basketball or soccer on weekends.