It's dark, Mum ___ be waiting for my return.

 There was something wrong with the network, or the e-mail____ earlier.

— Thank you so much for saving my son and bringing him home.— Don’t mention it. I only did what anyone else _______ in my place.

No student _________ go out of the school campus after ten o’clock at night without permission, according to the school regulations.

The demand that the law on gun ownership _____ be changed ___ is very strong.