If they really like a particular site, they may visit it often, but they are unlikely to devote a continuous half-hour or more to any one site the way you might read a traditional paper magazine in one sitting.
They may visit one site several times, but never spend a lot of time around it.
They can only visit a site once, and move on the others.
You need to sit through the movie without interruptions to enjoy it.
The final rule is not economically significant.
No one has ever met Jim.
A singer dances at a concert.
Some kids wearing shirts touch a railing.
The secretary closed the door without a noise.