4. The circuit in Fig. 4 has been connected for several seconds. Find the current (a) in the \( 4.00\mathrm{-V} \) battery, (b) in the \( 3.00\mathrm{-}\Omega \) resistor, (c) in the \( 8.00\mathrm{-V} \) battery, and (d) in the \( 3.00\mathrm{-V} \) battery. (e) Find the charge on the capacitor (2 points for each). (以科學記號表示且四捨五入至小數點3位)