问题
实验题
甲同学欲采用下列器材准确测定一个阻值大约为20 Ω的电阻。
A．直流电源(10 V，内阻不计)；
B．开关、导线等；
C．电流表(0～3 A，内阻约0.03 Ω)；
D．电流表(0～0.6 A，内阻约0.13 Ω)；
E．电压表(0～3 V，内阻约3 k Ω)；
F．电压表(0～15 V，内阻约15 k Ω)；
G．滑动变阻器(0～10 Ω，额定电流2 A)；
(1)为测量准确，电流表应选用________，电压表应选用________(填代号)；
(2)为了获得尽可能多的数据，该同学采用了“滑动变阻器分压接法”以调节电压，请画出正确的实验电路图，并将图中的元件按正确的实验电路图连成实物电路；
(3)闭合开关，逐次改变滑动变阻器滑动头的位置，记录与之对应的电流表的示数I、电压表的示数U。某次电流表、电压表的示数如图甲所示。
处理实验数据时，制作如图乙所示的I－U坐标图，图中已标注出了几个与测量对应的坐标点。请将与图甲读数对应的坐标点也标在图乙中，并在图乙中把坐标点连成图线；
(4)根据图乙描绘出的图线可得出这个电阻的阻值为R＝________ Ω。
答案
(1)D，F
(2)
(3)描点连线如图所示：
(4)18.0(17.5～18.5均可)
Teaching second grade is always a challenge. Each student arrives at school with his own needs and difficulties. One year a student called Billy 36 me with his behavior as well as his academic requirements. He struggled daily with his 37 emotions and often became angry or violent. I knew that, to make 38 progress, his emotions needed controlling. 
That day began as normal. I was preparing activities focused on dog themes 43 I was told that Billy had a 44 morning at home and I might need to get him 45 . As I was talking to his mom, Billy 46 into the classroom. To Billy’s 47 , Rocky immediately ran up to his new 48 , wagging his tail and licking Billy’s face with doggy affection. Billy couldn’t 49 Rocky’s charm (魅力) and began laughing as his anger melted away. 
B. pets C. botany D. diet 
43. A. after B. as C. when D. before
. jogged D. floated