单项选择题

Directions: In this part of the test there will be some short talks and conversations. After each one, you will be asked some questions. The talks, conversations and questions will be spoken ONLY ONCE. Now listen carefully and choose the right answer to each question you have heard and write the letter of the answer you have chosen in the corresponding space in your ANSWER BOOKLET.
Questions 1 to 5 are based on the following conversation. A. They are frustrating to use. B. They are expensive to operate. C. They can cause companies to lose business.D. They can be very convenient sometimes.