李明在探究“怎样用变阻器改变灯泡的亮度”时，连接的电路如图所示。闭合开关后，灯泡不亮，他用电压表进行电路故障检测，测试结果如表所示，则电路中的故障可能是

A．开关断路

B．开关短路

C．变阻器断路

D．灯泡断路

According to the Regulations on Import and Export Tariff of the People's Republic of China, the duty-paying value of an export item should be its normal ( ) price with the export duties deducted and examined, approved by the Customs.

A．FOB

B．CIF

C．CFR

D．FCA