external power to screen and multiple sensors

Hi, I want to connect multiple 5v sensors and a screen to an external power source. My question is can I connect all the grounds from the sensors and the screen to one ground pin of Arduino?

Thank you in advance

Yes you can. All Gnds must be connected to a common point which also connects to the external source, or to the external source directly.

thanks for you reply, do you mean a) can I connect all the grounds of the sensors to the power supply ground and forget about the Arduino ground pin ? b) all the sensor grounds must be connected to a single point with Arduino ground and power source ground ?