How many lines does a Shakespearean sonnet have?

Why does black lung aka arthur morgan let only jhon and abigail go and not sadie in the last chapter

This device blocks an opening along the base/floor of stairs or other walking or working surfaces where materials or body parts might otherwise inadvertently fall through. it should be 4 inches high, with not more than ¼ inch clearance above the floor

If the author of the gift of the magi had made the reader aware of the gifts that jim had purchased in the beginning of the story this would be an example of