Questions 11 to 18 are based on the conversation you have just heard.

A．She is shy when speaking in front of people.
B．She forgot to prepare the class.
C．She made a serious mistake in front of people.
D．She forgot to give a presentation.

A．Language was the first invention of mankind.
B．There was no greater invention than language.
C．Most of man’s inventions depended on language.
D．There were so many languages in the world.