Section A
Directions: In this section, you will hear 8 short conversations and 2 long conversations. At the end of each conversation, one or more questions will be asked about what was said. Both the conversation and the questions will be spoken only once. After each question there will be a pause. During the pause, you must read the four choices marked A, B, C and D, and decide which is the best answer.
听力原文：W: Why is there a big sign on the back of your door that says "keys"？
M: It's to remind me to take my keys when I go out because I'm always locking myself out by accident! It doesn't help though. Now I just forget to read the sign.
Q: Why is there a sign on the back of the door？
(12)

A. To remind the woman to lock the door when going out.
B. To remind the man to take his keys when going out.
C. To prevent the thief to break into when going out.
D. To prevent visitors from having an accident.