Paraphrase the following paragraph:
Since that advertising appears on screen only sporadically and only for a few seconds, it is not possible either to control its content or to insert warnings at the same time as the appearance of the advertisement on the screen on the dangers resulting from an excessive consumption of alcohol.
As such an advertising appears only rarely for several seconds, there is no way of checking the content of such advertising, nor of simultaneously inserting any warning of the dangerous consequences of excessive alcohol consumption at the time when the message appears on the screen.