Riding a skateboard is a phrase
A phrase can not have verb and subject together. riding a skateboard doesn't have subject. the others are clause.they have both subject and verb.
good luck.
predictive: I think that it will be sunny outside. I think I'm going to ace this test. I believe that my teacher has a pet.
non-predictive: I love playing outside! Math is my favorite subject in school. I am going to a movie this afternoon.
Answer:
Death and loss. Death is a clear theme in Dahl's The Witches, but the concept of loss manifests in many smaller ways, developing the theme throughout the book. The book opens with the boy's parents dying in a car accident in Norway, leaving him unscathed, orphaned, and in the care of his grandmother.