如图所示电路图来测一未知电阻R_x的阻值，现利用该电路进行实验：

（1）主要操作过程如下（将空格部分填写完整）

①先将滑动变阻器R₂的滑动触头调至 _________ ，单刀双掷S₂向1闭合，闭合电键S₁，调节滑动变阻器R₁和R₂，使电压表和电流表的示数尽量大（不超过量程），读出此时电压表和电流表的示数U₁和I₁；

②保持两滑动变阻器的滑动触头位置不变，将单刀双掷开关S₂向2闭合，读出此时电压表和电流表的示数U₂和I₂；

③由以上记录数据可计算出被测电阻R_x的表达式为 _________ ；

（2）误差分析：该电路能否消除由于两电表内阻造成的系统误差？

答： _________ （选填“能”或“不能”）；

（3） 按照电路图进行实物连线

Questions 6 to 10 are based on the following passage: (10 分)In previous generations, young people were under their parents’ control; now the teenagechildren of the West’s richest generation were ready for something to get excited about. The Beatlessimply put a spark to a fuse (导火线) that was waiting to be lit.Everything changed, and what changed for the Beatles was their lives and their working habits,in the midst of the hysterical (歇斯底里的)following the band attracted.. Because of the demand ofthe fans to see them perform, they played bigger and bigger venues (meeting places), especially inAmerica.But John, Paul, George and Ringo became increasingly unhappy that, because of the screamingof their fans, neither the band nor the audience could hear the music. Creatively frustrated and tiredof the pressures of life under siege (围攻) from their fans, they retired from playing concerts in 1966and decided to concentrate on recording.It was from this point that the brilliance of the Beades really began to reveal itself: they wouldrecord over their career some 200 songs. Never before nor since has any recording and writing groupeven developed and yet remained the same in the way the Beades did. Their songs never lost their universal appeal thanks to the warmth and timelessness of theirmelodies and lyrics.John and Paul were powerful singers with distinctive styles. It became apparent that, despite thefact that the songwriting credits were always equally attributed to them, Paul and John wrote andsang their own songs. George also contributed two or three of his own compositions to each of theBeatles eleven albums. Even Ringo wrote and sang the occasional song.

What can we learn about the Beafles’ music

A．It was a fine examPle of music for simple singalong songs.

B．Its appeal was not limited to any particular time or group of people.

C．It was simple in form but rich in meaning.

D．It reached a height which other pop music groups had never reached for their lyrics and melodies.