—How long have you been working as an assistant here?
— I finished middle school.
A. Ever since
B. Before
C. After
D. When
网友回答
(答案→)A. Ever since
B. Before
C. After
D. When
解析：词义辨析。A自从；B在…之前；C在…之后；D当…时；本题第一句的现在完成时说明所选之词必须能与现在完成时连用；只有ever since与现在完成时连用。句意：—她在这里做助手多久了？—自从我读完中学。根据句意说明A正确。