What is the superlative form of the adjective costly?

According to stephen hawking in the "origin of the universe" lecture, "why are we here" and "where did we come from" are questions that

On what evidence did you base your predictions? check the four boxes that apply. there is a rope around his neck. he is in alabama. his hands are tied behind his back. he is standing high above a river. the bridge is for railroads. some crimes are punished by hanging.

How does the illustration the reader understand the text? read the passage and study the image from sugar grinders.