Questions 14 to 17 are based on the following passage. At the end of the passage, you will be given 20 seconds to answer the questions. Now listen to the passage. Why does the professor mention a five story building

A．To correct a common misunderstanding about grasshoppers.
B．To help explain how well’ grasshoppers can jump.
C．To compare the size of grasshopper with that of other insects.
D．To show how quickly grasshoppers respond to danger.