Questions 18 to 20 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’s the main idea of the passage

A．Parents have more influential power on children’s achievement than teachers.
B．It’s sad to see so many parents not making the most of their children’s intelligence.
C．Teachers and educators ask parents not to educate their children before school.
D．Parents are afraid to teach their children at hom