填空题
{{B}}Questions 18-20{{/B}}
Decide which mobile phone package(s) is/are being described. Write the appropriate letter(s) on your answer sheet. Note that more than one answer may be possible.
A. pay-monthly B. pre-paid C. pay-as-you-go
填空题 You sign an agreement under this package.
填空题 This may be more expensive than paying monthly.
填空题 You buy more credit when you choose.