Complex sentence: Connecting the two electrodes is a wire (or other electrically conductive path, which may include some electrically powered device such as a light bulb) and completing the circuit and connecting the two chambers is a salt bridge or ion-exchange membrane.
Split into simpler sentences: Connecting the two electrodes is a wire (or other electrically conductive path). Completing the circuit and connecting the two chambers is a salt bridge or ion-exchange membrane.