What does “MJ” at last stand for? ( )

(单选题)According to the paragraph, a good listener would NOT ( ) (单选题)The main purpose of the passage is to ( ). (单选题)"Collar" in paragraph 1 is the equivalent of ( ). (单选题)( ) customers have an idea of the stores before shopping. (单选题)"Courteous" is opposite to ( ) . (单选题)"You clear your throat" in paragraph 2 means ( ). (单选题)What can we infer according to the text? ( ) (单选题)What can parents do according to the researchers? ( ) (单选题)What is the passage mainly about? ( ) (单选题)What can we learn from the passage? ( )