题目

People like different kinds of vacations. Some go camping, They swim, fish ,cook over a fire and sleep outside Others like to stay at a hotel in an exciting city They go shopping all day and go dancing all night Or maybe they go sightseeing go places such Disneyland ,the Tai Mahal or the bouvre . Some people are bored with sightseeing trips, They don’t want to be “tourists”. They want to have an adventure-a surprising and exciting trip .They want to learn something and maybe help people too .How can they do this? Some travel companies and environmental groups are planning special adventu某同学利用电源、电流表、电压表、开关，标有“50Ω 2A”字样的滑动变阻器和若干导线测定小灯泡的额定功率。其中灯泡上所标“0.3A”字样清晰可见，电压表0～15V挡损坏，小灯泡的额定功率估计为1.5W左右。画出灯正常发光的电路图，并简述判定灯正常发光的理由；