单项选择题
John is a nice guy，isn’t he？（降调）This question tag ____.（）
A.ask for clarification.B.ask for agreement.
单项选择题 Your birthday was last week.wasn’t it？（升调）This question tag ____.（）
单项选择题 Which of the following values have been discussed in the video（）
单项选择题 Which description is more polite（）
