孙中山祭文:“惟我皇祖 ,承天御世,钟奇孕灵……翦蚩尤于涿鹿,战炎帝于阪泉。挥斥八埏,疆里万国。用是奠基中夏,绥服九州。”这里的“皇祖”是指( )
A:黄帝
B:尧
C:舜
D:禹
如图所示,因线路故障,按通K时,灯L1和L2均不亮,用电压表测得Uab=0,Ubc=0,Ucd=4V.由此可知出现故障处为( )
A. No.It's on the first floor.
B Thank you.
C. Yes,it is.
D. It's next to my classroom.