单项选择题

Directions: In this section, you will hear 3 short passages. At the end of each passage, you will hear some questions. Both the passage and the questions will be spoken only once. After you hear a question, you must choose the best answer from the four choices marked A, B, C and D.

A. It can never be done even with high technology.
B. It is the best way to restore damaged eyesight.
C. It is a major achievement in eye surgery.
D. It can only be partly accomplished now.