Answer:
bring each tube close to the plastic ball and note any movement of the ball
Step-by-step explanation:
Electric fields can exert forces on objects, even if the objects involved are not touching. One way to demonstrate that electric fields exist around charged objects is to observe the effects of their forces at a distance.
Since the plastic ball of the electroscope is made of insulating plastic and is uncharged, it will be attracted to any charged object brought near it. So Jen can observe the effects of the tube's electric fields by bringing each tube close to the plastic ball and noting any movement of the ball. If the ball moves toward a tube, then the process that Jen used on the tube generated an electric field.