[填空题]
Electrocardiographs a-d9c zljk(ki/+ v31bddnt8usb+s hf-re often connectedg8q ibpm bv* 5pqbgk8a)8l9d 5 as shown in (Fig. Below). The leads are said to be capacitively coupled. A time constant of 3.0 s iqg)bq88 p9g bm55l8p kva i*bds typical and allows rapid changes in potential to be recorded accurately. If $C\,=\,3.0\mu F$, what value must R have? [Hint: consider each leg as a separate circuit.] $ \times10^{6 }\;\Omega$
