Bob ran down the road.
He fell over.

Bob ran down the road and he fell over.

The thunder roared.
The hobbits hid.

The hobbits hid because the thunder roared.

Bilbo slept in a cave.
The goblins attacked.

Bilbo, who slept in a cave soundly as the goblins attacked.

The cart came to a wheezing halt.
Gandalf strode into the hobbit hole.

The cart came to a wheezing halt and Gandalf strode into the hobbit hole.

Jim was interested in the idea.
He rang his friend.

Jim rang his friend because he had an interesting idea.

Owls are nocturnal.
This means they are active at night.
They have excellent eyesight.

Owls, which are nocturnal, have an excellent eyesight and this means they are active at night.