听一段对话,回答第 11、12 小题。答题完毕,请等待"嘀"的信号,进入第一篇短文。
(
B
)11. What was Mrs Lin doing when the murder happened?
A. Watching TV.
B. Doing some housework.
C. Chatting with her friend.
(
C
)12. Why did Mrs Zhang knock on Mrs Lin's door?
A. To have dinner with Mrs Lin.
B. To help clean the floor.
C. To ask for Mrs Lin's help.