I.单选题（20小题，每小题2分，共40分）
( ) 1.John is honest boy and good at making airplane model.
A. an; the B. an; / C. the; an D. an; an
( ) 2. There was _____ woman in the room, sitting and looking at me in the dark.
A. a 80-year-old B. an 80-year-old C. a 80-years-old D. an 80-years-old
( ) 3. ---What are these bottles ?
---Drinking water.
A. used by B. used to C. used for D. used up
