[填空题]
Suppose that you wishgc ocy+jg2os49d1t3 rnz; o 2w t+fnhf lwuyxi) ckr+m :x;.kv i8js d+7d:.a0fo apply a 0.25-V potential difference between two points on the human body. The resistanc v;0:.is7mx:nf xkfril w.u)dkf+ +chj8ay+d e is about $2000\Omega$, and you only have a 9.0-V battery. How can you connect up one or more resistors to produce the desired voltage? k$\Omega$
