两只“100W，220V”灯泡串联接在220V的电源上每只灯泡的实际功率是（）。
A、220W
B、100W
C、50W
D、25W
参考答案：D
— I had a really good weekend at my uncle's.
— _____. [ ]
A. Oh, that's very nice of you
B. Congratulations
C. It's a pleasure
D. Oh, I'm glad to hear that
