听第 10 段材料,回答第 17 至 20 题。 17 . When was the survey carried out? A . Several months ago. B . Several weeks ago. C . Several days ago. 18 . What was the score for friendliness as a whole? A . 8 out of 10. B . 7 out of 10. C . 6 out of 10. 19 . What's suggested to improve friendliness? A . Using some good phrases. B . Asking the caller's name. C . Removing hold music. 20 . What is probably the speaker? A . A customer. B . A manager. C . An interviewer.