A. He is wearing a yellow T-shirt and a cap.
B. She is wearing a skirt and a nice scarf.
C. He is wearing a black coat.
D. She is wearing gloves.
倩倩同学在做“探究小灯泡的亮度与电功率的关系”实验时,观察到小灯泡上标有“2.5V”的字样,灯的额定功率小于1W,滑动变阻器标有“20Ω1A”字样,而电源上却看不到电压值.