Simple/Compound/Complex Sentence?

When the tide goes out, seals and dolphins are sometimes stranded on beaches.

Tourists throw coins into the fountain for good luck and sometimes just for fun.

Marissa watered the plants then fertilized them.

The hikers, who had not yet had lunch, were getting hungry.

The fog rolled in, and everyone felt cold.

Even after we stopped shouting, we could hear the echoes in the mountains.

The theme park whose rides include teacups is located in Florida.

George thanked the presenters and quickly sat down.

Laurel discovered a box of old photos in the back of the closet.

Calcium and vitamin D are important for strong bones, so I drink milk.

William likes horror stories, so he has been reading Edgar Allan Poe's short stories.

The library hired a new assistant, but I have not met him yet.