客房清洁卫生的生化标准，通常是由（）的有关人员到饭店作定期或抽样测验与检验。

A、环境保护局

B、质量技术监督局

C、卫生防疫站

D、医院

— Why did you laugh just now？

— Ted wanted to tell us ______ very funny story, but he forgot ______ ending himself.

A．a; an

B．the; the

C．the; a

D．a; the