题目

小童同学要探究通过导体的电流与其电阻的关系。现有一个满足实验要求的电源，一个滑动变阻器，一个电流表和一个电压表，一个开关，若干定值电阻、导线。请帮助他选用上述实验器材。（1）面出电路图；（2）写出实验步骤；（3）画出实验数据记录表格。 答案：【答案】见解析【解析】该实验利用了控制变量法，要使通过电阻两端的电压保持不变，必须把各种阻值已知的定值电阻分别与滑动变阻器和电流表串联起来，然后利用滑动变阻器调节定值电阻两端的电压保持不变，用电流表测出通过定值电阻的电流分析比较即可。（1）用电压表与定值电阻并联，测定 Bill is from Australia. He lives in Sydney. He can speak French and English, but he can' t speak Chinese. He has a pen pal in the United States. Her name is Lisa and she lives in New York. Bill' s favorite sport is basketball and he can play the guitar. Lisa' s favorite sport is tennis. She can't play the guitar, but she can play the piano and sing very well.1.Bill is from_______.A. Australia B. France C. the United States D. the UK2.Lisa is an ________.A. Chinese B. American C. English D. Japanese3.What languages does Bill speak?A. Chinese B. French C. English D. B and C4.What is Bill' s favorite sport?A. tennis B. volleyball C. soccer D. basketball5.Which sentence is NOT right(正确的)?A. Bill has a pen pal in the USA.B. Bill can play the piano and Lisa can play the guitar.C. Bill and Lisa like different sports.D. Lisa lives in New York.