Directions: In this part of the test, you will hear several short talks and conversations. After each of these, you will hear a few questions. Listen carefully because you will hear the talk or conversation and questions ONLY ONCE. When you hear a question read the four answer choices and choose the best answer to that question. Then write the letter of the answer you have chosen in the corresponding space in your ANSWER BOOKLET.
12)

A． A. The possible existence of life on other planets.
B． B. Methods for building powerful new telescopes.
C． C. A technical problem that astronomers can’t solve.
   
D． D. The discovery of planets orbiting distant stars.
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