Questions 11 to 13 are based on the following passage. At the end of the passage, you will be given 15 seconds to answer the questions.
Now, listen to the passage.
What is the main idea of this passage

A．In every school there is a "top" crowd that sets the pace.
B．It is a mistake to follow the "top" crowd blindly.
C．At one time or another you probably did something you knew to be wrong.
D．People who follow the "top" crowd are endangering their very lives.