[填空题]
A circuit contains a single 250-pF capace okof(7/vy d;itor hooked across a battery. It isbhdwj:4j(k4;d)in + x 3epm wr desired to store three times as much enerm+nhprwjd4: wd (3e)4xijk b; gy in a combination of two capacitors by adding a single capacitor to this one.
How would you hook it up?
what would its value be? pF