题目

如图所示，B为理想变压器，接在原线圈上的交流电压U保持不变，R为定值电阻，电压表和电流表均为理想电表。当开关S闭合后，下列说法正确的是    A．电流表A1的示数变大    B．电流表A2的示数变小                                            C．电压表V的示数变小    D．灯泡L1的亮度变亮 根据句意及汉语提示写出正确的单词。1. —Do you like black _____ (鞋), Jim?    —Yes, I do.2. —How many markers are there in your pencil case?    —_____ (八支).3. —Is this hat new?    —No, it's _____ (旧的).4. Danny and Tom _____ (指着) to the stars (星星).5. There are four _____ (双) of socks in the bag.