Passage Two
Questions 29 to 31 are based on the passage you have just heard.

A) To keep it longer. C) To make it rougher.
B) To give it a particular taste. D) To fasten the process.

A．They use unemployment rates to judge the decline measured by the index.
B．They use the interest rates to confirm the growth of economy.
C．They use percentage to represent the changes weighed by the index.
D．They use stocks as the measurement of development in market.