Questions 8 to 10 are based on the following conversation. At the end of the conversation, you will be given 15 seconds to answer the questions.
Now listen to the conversation. Which of the following is NOT an evidence of some people’s carelessness in daily communication
A．Their intonation is poor sometimes. B．Their choice of words is poor. C．Their speech is full of grammatical mistakes. D．They fail to pronounce some words properly.