Questions 12 to 15 are based on the conversation you have just heard.

What does the woman think is important in the whole operation（）

A．It can change into acids causing damage to their outer covering.
B．It greatly reduces their resistance to the attacks of bacteria.
C．It makes their nerves and blood vessels more sensitive to acid food.
D．It combines with food particles to form a film on their surface.

A．She decided to get married in three years.
B．Her mother objected to Eric’s flying lessons.
C．She insisted that Eric pursue graduate studies.
D．Her father said she could marry Eric right away.