In a parallel circuit if a light bulb goes out the rest are fine because they each have independent routes to the battery. But in a series circuit when a light bulb goes out the rest goes out because the current is going in one pathway. To tell the difference of if it closed or opened the circuit, you have to know what they mean. Closing a circuit means a complete electrical connection, the light bulbs will light and electricity will flow. Opening a circuit means the opposite. If the all the light bulbs have stopped working then the circuit is not complete, therefore it's open.
In a parallel circuit if a light bulb goes out the rest are fine because they each have independent routes to the battery. But in a series circuit when a light bulb goes out the rest goes out because the current is going in one pathway. To tell the difference of if it closed or opened the circuit, you have to know what they mean. Closing a circuit means a complete electrical connection, the light bulbs will light and electricity will flow. Opening a circuit means the opposite. If the all the light bulbs have stopped working then the circuit is not complete, therefore it's open.
The answer is number two extinction happened, this was the time dinosaurs went extinct ebcause lack of sun because oh how much dirt was blown into the earth atmosphere becuase of the asteriod, third option is talking about big bang theroy so that dosnt apply!