SECTION A CONVFRSATIONS In this section you
will hear several conversations. Listen to the conversations carefully and then
answer the questions’ that follow.
Questions 1 to 4 are based on the
following conversation. At the end of the conversation, you will be given 20
seconds to answer the questions. Now listen to the
conversation.
How did the scientists establish the existence of the planets
A．They studied the gravitation in the appearance of the parent stars. B．They were able to see the planets with a telescope. C．They compared the parent stars to the Sun. D．They sent astronauts on a mission into space.