a) I thought this was a nude beach.
b) I thought you two were a team.
c) I thought you didn't understand me.
d) Rachel and I are going to watch a movie now, and we were just wondering if you want/would like to join us.
eiii) He has never told you that?
fiii) I have never left this country before.
a) What do you have in mind?
b) What is on your mind?
c) Bear in mind ....
a) I have been waiting for 4 hours (Continuous action)
b) I have been waited for 4 hours (Ungrammatical)
c) I have waited for 4 hours (Fact)
If we were to call the server every five second, we would probably end up with denial of service because the server would think that you were trying to hack it for information.