Dear ailicec, thank you for your help.
Is anybody else in my situation?

Dear ywan459, thank you for your many suggestions!
About delaying the offer, I was wondering if they usually get upset at students, who don't accept their offers right away. Because of course I would like to accept an offer from a university, which I have applied to, but at the same time I would like to get all the results first.
Also, how long can I ask them to wait?

Hi everyone, I'm applying for PhDs in the UK. I was wondering what happens if I receive an offer, but I still want to wait for the results of other applications I made. Will I have a deadline to accept the offers? Or should I discuss the issue with the departments that accept me? I would like to have a full picture of my applications before deciding, and I know some of them answer a lot earlier than others.