_____ alarm clock and _____ computer are on the desk．

A．A；a                   B．An；a                  C．A；an                    D．An：an

--Lily，open _______door，please．

--I'm coming．

A．a                 B．an                C．the               D．不填

--What can I do for you，madam?

--_____ pair of shoes，please．

A．A             B．An             C．The               D．不填

—By the way, have you got ______ e-mail address?

—Oh, yes, it is swimonland @ hotmail.com.

A．a             B．an                  C．the                   D．/

________Browns were having dinner when the telephone rang

A．A              B．An                 C．The               D．/